US2895188A

US2895188A - Continuous casting apparatus

Info

Publication number: US2895188A
Application number: US599283A
Authority: US
Inventors: Wittmoser Adalbert
Original assignee: EISENWERKE GELSENKIRCHEN AG FA
Current assignee: EISENWERKE GELSENKIRCHEN AG FA; EISENWERKE GELSENKIRCHEN AG Firma
Priority date: 1953-01-23
Filing date: 1956-06-04
Publication date: 1959-07-21
Anticipated expiration: 1976-07-21
Also published as: NL93836C; GB784286A; BE525734A; FR69840E; CH318907A; GB750709A; NL184206B; CH340959A; BE548199A; FR1091600A

Description

July 2l, 1959 FiledJune 4, 1956 A. WITTMOSER CONTINUOUS CASTING APPARATUS 4 sheets-sheet 1 INVENTOR. WMM-Mmmm www. s. Am/W July 2l, 1959 4 A, W|TTMQ5ER 2,895,188

v CONTINUOUS CASTING APPARATUS Filed June 4, 1956 4 sheets-sheet 2 INVENTOR.

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CONTINUOUS CASTING APPARATUS 4 Sheets-Sheet 3 lNV-ENTOR. MMM Mmmm udwul s. 9m

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' Filed June 4, 1956 CONTINUOUS CASTING APPARATUS 4 sheets-sheet 4 INVENTOR.

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2,895,188 Patented July 21, 1559 United States arent Oilice CONTINUOUS CASTING APPARATUS AdalbertV Gelsenkirchen, Germany, assigner Y to Firma Eisenwerke yGelsenkirchen Aktiengesellschaft, Gelsenkirchen,l Germany The present invention relates to apparatus for continuous casting of materials, and this application is alcontinuation-in-part of co-pending applications Serial No. 405,- 425, filed January 21, 1954, now abandoned, and Serial No. 517,811, led June 24, 1955, now Patent No. 2,762,096, dated September 11, 1956.

Morev particularly, the -invention relates to a casting apparatus `including a continuous casting mold `and a discharge vessel for discharging molten metal in aV controlled manner into the continuous casting mold.

The present apparatus provides for the delivery of molten metal or other casting material into a casting mold for forming products` having either asolid or a hollow cross section, the present device being of the type wherein a movable discharge vessel containing the casting material is arranged for discharging the casting material into the mold as the level of the casting material in the continuous casting mold drops. t

Such types of movable discharge vessels, which may be moved for changing the same in a desired position over the surface of the metal `or other material in the mold, are of particular advantage in the manufacture of hollow bodies such as tubes, pipes and the like, andv of products having a solid cross section of which the cross section in one direction is relatively narrow and in the otherdirection is relatively long. An advantage of the present apparatus residesiin vthe fact that lonly a few outlet openings are necessary. in the discharge vessel in spite of' largesurface areas of the metal in the mold device. In this way there is made possible a uniform and rapid distribution of the outflowing metal over the entire metal surface in the interior of the mold.

In known devices of the above type, a discharge vessel Vmay be providedwith individual discharge openings extendingthrough the bottom thereof. These channels or Vnozzles are formed with fixed passage cross-sections and 'are arranged verticallyt'or inclined in position over the mold cavity or over the walls of the outer mold member vor of the core thereof. The amount of molten metal therefore depends upon the particular cross-section of the dscharge openings, and a variation in the amount of the delivered molten` metal is produced by a corresponding degree of tilting vof the delivery conduit which supplies the molten metal to the discharge vessel. In this way a greater or lesser amountof the molten metal ows into the discharge vessel from the supply-vessel, `By raising -the 'level vof the metal in the discharge vessel, the pres- `sure of the molten metal isincre'ased, which causes an `increase in the rate offlow of the molten metal through ,the discharge openings.

in spiteof the increase in the speed of ow of the molten metal through thev outlets due to the increased staticpressure of the metal, the desired variation in the amount of molten metal discharged cannot be carried out with suliicient rapidity as is necessary and desirable in order to maintain a constant level of the casting material in the mold.

It is, therefore, an object of the present invention to overcome the above disadvantages in continuous casting devices of the above-mentioned type.

It is another object of the present invention to provide a continuous casting apparatus wherein the level of the casting material in the mold may be kept relatively constant.

It is still another object of the present invention to provide a discharge vessel for use in a continuous casting apparatus which allows for rapid changes in the rate of discharge of the casting material therein into the continuous casting mold inaccordance with variations in the rate of delivery of the molten material t-o the discharge vessel.

It is still a further object of the present invention to provide a discharge vessel of the above type wherein foreign substances may be kept from iiowing with the casting material from the discharge vessel into the casting mold.

The objects of the present invention also include the provision of a casting apparatus capable of uniformly supplying molten metal to the casting mold.

It is yet another object of the present invention to provide a continuous casting apparatus which is so constructed as to enable the operator to observe the pouring of the molten material, particularly the place at which the stream of molten metal impinges upon the liquid metal already in the mold. j

Other objects and advantages will become apparent from the lfollowing description and the appended claims.

With the above objects in View, the present invention relates to a discharge control device for use in a continuous casting apparatus which comprises a device for controlling the discharge of casting material into a continuous casting mold, comprising a vessel having an inlet at its top and having a side Wall, the vessel being formed in the side wall, with at least one elongated outlet extending substantially axially of the vessel, whereby the rate of discharge of the casting material from the vessel through the elongated outlet may be rapidly varied in accordance with the rate of delivery of casting kmaterial to the vessel through the inlet thereof.

According to a preferred embodiment of the present invention mold means are provided which define an upwardly extending annular space adapted to receive molten metal, and moltenv metal supply means are arranged above the mold means and are at least partly within an upward annular extension of this annular space. That part of the supply means which is in the upward annular extension is formed with outlet means through which molten metal received by the supply means may tiow into the annular space The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method'of operation, together with additional objects and advantages thereof,

vwill bev best understood from the following'description 'of specic embodiments when read Vin connection with :slots 21.

Fig. 3 is a fragmentary view partly in section of an embodiment of the present invention;

Fig. 4 is a fragmentary plan view of the discharge vessel shown in Fig. 3;

Fig. 5 is a fragmentary View in section vof another embodiment of a discharge vessel constructed in accordance with the invention;

Fig. 6 is a view of the device shown in Fig. 5 taken in the direction of the arrow shown in Fig. 5; v

Fig. 7 is a plan view of a portion of a discharge vessel constructed in accordance with the invention incorporating a trap device;

Fig. 8 is a View 4of the device shown in Fig. 7 taken along the line VIII-VIII; and

Figs. 9 to 11 are fragmentary plan views, respectively, of three embodiments of a supply vessel according to the present invention.

Referring now to the drawings, and particularly to Fig. l, there is shown a continuous casting apparatus which includes a separable continuous mold device 10 having a lower outer mold member 11 and an upper outer mold member 12, and having upper and

lower core members

13 and 14, the mold members being arranged to to provide a mold cavity 15 therebetween in which a metal pipe, for example, may be continuously cast. In the casting apparatus shown in Fig. l a -mold for making socket pipe is shown, the mold being so arranged that a socket cavity 16 is defined at the lower portion thereof for making the socket portion of a socket pipe. In the operation of the particular mold for continuously forming cast pipe as illustrated, the lower portion of the mold is gradually lowered in a direction away yfrom the upper mold portions as the shaft of the formed pipe solidies, thereby lowering the level 17 of the molten metal at the top of the mold cavity 15. As the level 17 of the molten metal drops, additional molten metal is discharged from the outlets of the discharge vessel 18, as more fully described herein. It is to be understood that the maintenance of level 17 at a constant height can be continuously carried out by the continuous discharge of molten metal from discharge vessel 18 as the level 17 drops.

The `supply of molten metal to discharge vessel 18 may be carried out in any suitable manner, the means illustrated being a supply vessel 19 which is movably supported above a conduit 22 from which the molten metal flows into the discharge vessel 18. The supply vessel 19 is tiltable about a horizontal axis so that a greater or lesser amount of molten 'metal may be delivered to the conduit 22 and consequently to the discharge vessel 18 as desired.

ADischarge vessel 18 may itself be movably mounted above the casting mold 10, and may, if desired, bemade l rotatable about its axis, so that the discharge outlets there- 1n may be arranged above any desired portion of the open top of the mold cavity 15.

Discharge vessel 18 Imay be provided with one or more discharge openings of the type hereinafter more fully described and shown in the drawings, and the vessel may be either of annular form as shown in the drawings, or it may be merely of cup-shaped form of any desired peripheral shape. It is necessary only that the shape of discharge vessel 18 be such that the discharge openings thereof are properly arranged above the continuous casting mold 10 to provide for discharge of the molten metal into the mold cavity 15.

Fig. 2 is a plan view of one form of a discharge vessel which is of annular shape and is 'provided at spaced intervals around its periphery with elongated outlet slots 21, the discharge vessel 20 being formed with a central conical wall which defines between itself and the outer wall a trough 23 in which the molten metal may be poured from the supply vessel by a forked conduit 22, and from which the molten metal is discharged through The number and arrangement of the slots 21 may 'be varied as desired, and, in fact, only a single slot may be provided, in which case the discharge of molten metal therethrough in a uniform manner into the mold cavity of the type shown in Fig. 1 may be accomplished by rotating the discharge vessel about its axis by any suitable means.

The arrangement of the discharge vessel with respect to the continuous mold is shown in greater detail in Fig. 3. As shown in Fig. 3, the discharge vessel 4 which is of annular form is so arranged that the molten metal 24 contained therein is discharged through slot 5 directly into the Imold cavity 3, which is defined between the outer mold member 1 and the core mold member 2. The discharge slots 5 are formed preferably in circumferentially spaced arrangement in the outer wall 25 of discharge vessel 4. Slots 5 may have uniform width along their lengths, or they may be of increasing width as they extend upwardly toward the top of outer wall 25. Preferably, slots 5 extend all the way to the top of outer wall 25 so that they are open at their top ends. The lower ends of slots 5 are preferably spaced above the bottom 6 of the discharge vessel 4, in order to provide for a continuous ring of molten metal at the bottom of the discharge vessel 4.

Fig. 4 shows a plan view of the device shown in Fig. 3, the curved formation of the discharge vessel walls and the trough formed thereby as well as the top of slot 5, being more clearly illustrated therein.

The embodiment of the discharge vessel 4a shown in Figs. 5 and 6 differs essentially from that shown in Figs. 3 and 4 in that the lower portion 5a of the outlet slots 5 have a particular width for the casting of a tubular cast article, while the upper portion 5b of the slots is widened in a stepwise manner in order to provide for the casting of a socket portion of the tubular article. Such socket casting is carried out at the beginning of the casting operation by raising the level of the molten material in the discharge vessel 4a above the stepped portion `of the slots, so that a relatively greater amount of molten material may be initially discharged into the casting mold for forming the relatively larger volume of the socket portion of the pipe.

In the embodiment shown in Figs. 7 and 8, the annular discharge vessel 4b is provided with a slag catching member or trap 7 which is arranged adjacent each slot 5c in the manner shown in Fig. 8, the slag catching member 7 being preferably of a domed or roof-shaped form, the ,arrangement of member 7 in the vessel 4b being such that foreign substances such as slag particles are prevented thereby from passing through the discharge slots 5c into the molding device.

The device constructed in accordance with the invention operates in such manner that when the surface of the molten metal drops a substantial amount in the continuous casting mold 10, the level of the molten metal in the discharge vessel 18, as shown in Fig. 1, is increased by adding additional molten metal thereto, and in this way the molten met-al therein flows out of the lateral outlet slots 5, such as shown in Fig. 3, without any delay, so that a greater amount of molten metal is discharged into the continuous casting mold 10. As a consequence, the level of the molten metal in the casting mold is quite rapidly brought again to the desired or necessary height.

By virtue of the arrangement shown in the embodiment of Figs. 5 and 6, it is possible to control the relative amounts of the molten metal discharged through the outlet slots 5 where at one time a comparatively rapid discharge i's required While at another time `a substantially slower discharge is desired, as, for example, in the casting of socket pipes. In this way, as pointed out above, in the casting of the socket portion of the pipea relatively great amount of ymolten metal may be initial-ly discharged into the casting mold, while thereafter in casting the shaft portion of the socket pipe which adjoins the socket portion, a smaller amount of casting materialper unit of time may be discharged.

This process is achieved by initially providing a comparatively Ihigh level of molten metal in the discharge vessel 4a (Fig. 5), so that thel the level of the casting material therein is so high that the casting material ows not only through the lower portion 5a of the outlet slots which are of normal width, but also through the widened upper portion 5b lof the slots 5. Shortly before the end of the process of casting of the socket portion, or duringthe casting of the transition portion between the socket and shaft portions of the pipe, a lesser amount of casting material is delivered to the discharge vessel 4a, so that the level of the molten material therein drops below the vwidened portion 5b of the outlet slots 5 therein. The delivery of the molten material at the reduced rate is then substantially maintained in casting the shaft portion of the pipe.

In similar manner,other hollow articles having other types of lVariable cross section may be cast.

In order to provide for uniform distribution of the molten metal delivered to the discharge vessel, 4, the bottom of the discharge vessel is preferably made deeper than the lower end of the slots 5 in the side wall, as Ishown inFig. 3. In this way a continuous ring of molten casting material is provided in the bottom of the discharge kvessel so that all of the discharge Slots 5 discharge molten material simultaneously as soon as the level of the molten material reaches theV bottoms of the slots 5 which are arranged at the same level.

By virtue of the trapping device shown in the embodiment illustrated in Figs. 7 and 8, the trapping of foreign substances such as slag particles by the trap 7 prevents the foreign substances from flowing into the casting mold,` Iand this feature provides for maintenance of a higher quality of the products cast in the casting mold.

Figs. 9 to ll are fragmentary plan views, respectively, of three embodiments of a supply vessel according to the present invention.

In the embodiment shown in Fig. 9, the supply vessel, which may be mounted for rotation relative to the mold in the direction of the arrow, has an annular portion 101 and a transverse portion 105 which projects into an upward annular extens-ion of the annular mold chamber 102 which is the annular space formed between outer and

inner mold walls

103 and 104. The transverse portion has a side wall which is formed with at least one substantially vertical slot 106 through which molten metal received by the vessel may ow into the mold chamber 102. The slot may have any suitable configuration, as, for example, any one of the congurations shown in the previously described embodiments wherein the width of the slot increases from the bottom toward the top of the vessel. Also, a trap member 113 may be arranged in the vessel at the juncture of the annular and

transverse vessel portions

101 and 105 for preventing the entry of slag or other foreign substances in the molten metal into the transverse portion 105, thus preventing the discharge of such foreign substances through the slot.

In this way, the stream of -metal issuing from the slot may be caused to impinge upon the liquid already in the mold chamber at a place spaced from the inner and outer mold walls, particularly if the mold chamber is of such Width that if the molten metal were to issue from an opening formed in the annular vessel portion instead of the transverse vessel portion, such stream would impinge upon the metal already in the mold chamber at point relatively near the inner mold wall 104.

While the embodiment shown in Fig. 9 is one wherein the annular vessel portion is encompassed by the upward annular extension of the mold chamber, the transverse vessel portion thus being an outwardly extending one, it will be understood that the annular vessel portion may encompass this upward annular extension, in

Cil

which case the transverse vessel portion would be an inwardly extending one. The provision of the outlet slot in such inwardly projecting transverse portion would thus enable the stream of molten metal to impinge upon the metal already in the mold chamber at a point spaced from the outer mold wall 103.

It has been found that although the transverse portion projects over the mold chamber, it is still a very simple matter for the operator to observe the surface of the molten metal within the mold chamber, even where the supply vessel is provided with two, three, four or more transverse portions, particularly when the supply vessel is rotated relative to 4the mold means.

Another embodiment of a supply vessel according to the present invention is shown in Fig. l0 wherein

parts

101a, 102a, 103a, 104a, 105a and 11341 correspond, respectively, to

parts

101, 102, 103, 104, and 113 of the above described embodiment. The instant supply vessel however differs from the one shown in Fig. 9 in that the transverse portion 105a is formed with two side walls facing the outer and inner mold walls 103a and 104g, respectively. Each of these side walls is formed with an outlet '

slot

107, 108 so that molten metal may issue therethrough into the mold chamber 102a'.

In the embodiment shown in Fig. ll, wherein parts 101k, 10212, 103]), 10417, 10511 and 113b correspond, respectively, to

parts

101, 102, 103, 104, 105 and 113 of the embodiment shown in Fig. 9, the outlet slots are angularly displaced relative to each other. However, in this embodiment, as in the one shown in Fig. l0, one of the slots is in a side of the transverse portion which faces an upwardly extending cylindrical projection of the inner wall 10415 of the mold, and the other slot is in a side wall of the transverse portion which faces an upwardly 'ex tending cylindrical projection of the outer wall 103]: of the mold. lf desired, a dellector or baffle plate 111, 112 may be provided for each slot for preventing the stream of molten metal issuing from each slot from impinging upon the walls of the mold before dropping into the mold chamber 10211.

The present invention provides several distinct advantages, as follows:

There is assured, by virtue of the invention, an immediate proper proportioning of the amount of molten metal discharged into the mold cavity, in accordance with a greater or lesser tilting of the supply vessel or conduit which delivers the molten metal to the discharge vessel, and this result can be achieved as well in the continuous casting of workpieces which have uniform cross sections, as well as in the continuous casting of workpieces which have markedly different cross sections, as, for example, socket pipes. Further, the manufacture of the discharge vessel is considerably simplified, since in accordance with the invention the outlet slots may be easily formed in the side wall of the discharge vessel so as to have the proper cross-section, in contrast to the known arrangements wherein discharge openings are provided in the bottom of a discharge vessel, the discharge openings of these devices being made of a particular calibrated cross-section to provide for a particular speed of casting.

Furthermore, there is provided in accordance with the invention greater ease of cleaning of the discharge vessel, with consequent greater durability of the vessel, because the removal of the residue of the molten material after the casting process can be carried out much more easily and thoroughly than in the case of discharge nozzles or openings of small cross-section as provided in the prior art devices.

Also, the influence of the flowing quality of the molten material on the casting process is reduced, since it is possible in the case, for example, of thickly flowing molten material to fill the discharge vessel to a higher level and in that way the amount of discharged molten met-al per unit of time may be kept uniform.

Finally, a further advantage resides in the -fact that in the forming of hollow bodies by means of an annular discharge vessel, only a few suiciently large slots suffice for satisfactory discharge of molten material into the mold.

It will be understood that each of the elements described above, or two or more together, may also nd a useful application in other types of liquid discharge devices dilering from the types described above.

While the invention has been illustrated and described as embodied in continuous casting apparatus for making pipes, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. In a metal casting apparatus for casting tubes or the like, in combination, mold means including concentric cylindrical inner and outer wall means forming between themselves an upwardly extending annular space adapted to receive molten metal; and a molten metal supply vessel arranged above said mold means, said vessel having an annular portion located exteriorly of an upward annular extension of said annular space and at least one transverse portion projecting into said upward angular extension, said transverse portion being so constructed and arranged as to have at least two side walls facing au upwardly extending cylindrical projection of said inner wall means and an upwardly extending cylindrical projcction of said outer wall means, respectively, each of said side walls being formed with at least one substantially vertical slot through which molten metal received by said vessel may ow into said annular space so that the rate of discharge of molten metal through said slots is dependent upon the height of the liquid level within said vessel, whereby the rate of discharge of molten metal from said vessel through said slots may be varied in accordance with the r-ate of delivery of molten metal into said vessel. l

2. The combination dened in claim 1, and deector means carried by said vessel and being arranged 'in the path of a stream of molten metal issuing from each of said 4slots in such a manner that the molten metal impinges upon said dellector means and thereafter drops into said angular space.

3. The combination defined in claim 2 wherein said deector means are constituted by a plurality of deector plates associated with each of said slots, respectively.

References Cited in the file of this patent UNITED STATES PATENTS 125,044 Guthrie Mar. 26, 1872 2,224,303 Junghans Dec. 10, 1940 2,659,120 Harter et al Nov. 17, 1953 2,757,425 Duncan et al. Aug. 7, 1956 2,762,096 Wittmoser Sept. 1l, 1956 2,793,410 Junghans et al. May 28, 1957 FOREIGN PATENTS 746,211 Germany June 15, 1944 911,065 Germany May 10, 1954 1,079,898 France May 26, 1954 1,091,600 France Oct. 27, 1954