US3785540A

US3785540A - Golf tee type stopper for molten metal discharging

Info

Publication number: US3785540A
Application number: US00257446A
Authority: US
Inventors: W Donnithorne; W Creswick
Original assignee: Algoma Steel Corp Ltd
Current assignee: Algoma Steel Corp Ltd
Priority date: 1972-05-24
Filing date: 1972-05-26
Publication date: 1974-01-15
Anticipated expiration: 1991-01-15
Also published as: CA964035A

Abstract

A stopper means for use in controlling the flow of molten metal through the teeming aperture of a bottom pouring ladle, said stopper means being movable between a closed and open position when in said aperture, said stopper means comprising a neck of heat resistant material, such as zirconia, dimensioned to extend through the teeming aperture with a gap therebetween, an enlarged head attached to one end of said neck and adapted to close the teeming aperture in the closed position thereof and a dispenser attached to the other end of said neck having channels extending therethrough in a direction generally axially of said neck, said channels generally converging to a point remote from said neck whereby when said stopper means is located in said aperture, said head is located in said ladle and said dispenser is located beneath said ladle.

Description

Donnithorne et al.

GOLF TEE TYPE STOPPER FOR MOLTEN' METAL DISCHARGINGv [75] Inventors: William C. Donnithorne; William E. Creswick, both of Sault Saint Marie, Ontario, Canada [73] Assignee: The Algoma Steel Corporation,

Limited, Sault Saint Marie, Ontario, Canada [22] Filed: May 26, 1972- 21 Appl. No.: 257,446

[30] Foreign Application Priority Data May 24, 1972 Canada 142834 52 Us. (:1. 222/559, 251/144 [51] Int. Cl B22d 37/00 [58] Field of Search 222/559, DIG. 4, 222/DIG. l, DIG. 7, DIG. 21, 251/144 [56] References Cited UNITED STATES PATENTS 2,863,189 12/1958 Beck ZZZ/DIG. 4 3,310,851 3/1967 Stiteler 222/DIG. 21 3,502,249 3/1970 Wagstaff... 222/DIG. 4 3,480,186 11/1969 Grosko 222/DIG. 7 460,575 10/1891 Grace 222/DlG. 4 3,354,939 11/1967 Calderon ZZZ/DIG. 4

[ Jan. 15, 1974 3,651,825 3/1972 Sury 222/1310. 4

FOREIGN PATENTS OR APPLICATIONS 1,146,218 5/1957 France 222/D1G. 21

Assistant Examin er Dai/id A. Scherbel Attorney Spencer arid Kaye 5 7] ABSTRACT A stopper means for use in controlling the flow of 'molten metal through the teeming aperture of a bottom pouring ladle, said stopper means being movable between a closed and open position when in said aperture, said stopper means comprising a neck of heat resistant material, such as zirconia, dimensioned to extend through the teeming aperture with a gap therebetween, an enlarged head attached to one end of said neck and adapted to close the teeming aperture in the closed position thereof and a dispenser attached to the other end of said neck having channels extending therethrough in a direction generally axially of said neck, said channels generally converging to a point remote from said neck whereby when said stopper means is located in said aperture, said head is located in said ladle and said dispenser is located beneath said ladle. i

25 Claims, 5 Drawing Figures {:Illlillllllllllllllllmuw- PATENTEBJAN 1 5 I974 3.78550 sum v1 [1F 2 FIG-I.

DISCHARGING The present invention relates to ladles for use in pouring molten metal, particularly molten steel during the casting thereof into molds. In particular the present invention relates to an improved stopper means for use in controlling the flow of molten metal through the teaming aperture of a bottom pouring ladle in the castingof metal, particularly steel.

In the casting of steel from, for example, a basic open hearth steel heat, the steel heat is tapped from the furnace into a ladle in which it is transported to the casting molds and from which it is subsequently poured into the casting molds. Practically all basic open hearth steel is cast from bottom pouring type ladels, which ladles have a stopper assembly acting as a valve to control the flow of metal through the nozzle of the teaming aperture at the base of the ladle, the size of the nozzle being sufficient to produce a smooth solid stream of molten metal through the aperture as free from turbulence and spraying as possible. A typical nozzle is formed by a cylindrical pipe made of zirconia possessing properties very similar to the fire brick liner of the ladle and being very dense to reduce orifice erosion and at the same time to provide a seat for the stopper rod of the stopper assembly. A typical stopper rod asp sembly consists of a steel stopper rod, refractory stopper sleeves, refractory stopper head and steel stopper head pin by which the stopper head is keyed to the stopper rod. The stopper head and nozzle constitute a valve controlling the flow of molten steel through the teeming aperture. The stopper rod is located completely in the ladle and extends vertically from the teeming aperture to above the top of the ladle and is raised and lowered to open and close the teeming aperture by a ladle rigging which consists essentially of a barrel within which a square or cylindrical slide is operated by an appropriate lever arrangement placed at the lower end. More recently hydraulic cylinders mounted on the ladle rigging have been substituted for the manually operated lever in many installations. The stopper rod is bolted at its upper end to a rigid stopper carrier (goose neck) which in turn is keyed or bolted securely to the upper end of the slide. The entire rigging is attached to the side of the ladel shell in a manner that permits a certain amount of lateral movement of the stopper with respect to thenozzle and the rammed well which surrounds the nozzle through proper adjustment of the adjustingwheel and screw placed within reach of the steel pourer. Such a bottom pouring ladle containing the stopper rod assembly is shown in FIGS. 16-28 on Page 491 of the book entitled Making, Shaping and Treating of Steel," EighthEdition published by United States Steel and edited by Harold E. McGannon.

However, such a stopper rod assembly is subject to a number of disadvantages including the substantial cost of the stopper rod assembly which has to be replaced after each heat is poured from the ladle and further the control by the stopper rod of the precise flow pattern of the metal through the nozzle when it is moved to the open position is not precise. It hasfurther become desirable in the steel making process to bubble gases, particularly inert purging gases such as argon through the molten metal in the ladle and many methods have been proposed includingincorporation of a gas pervious but liquid metal impervious fire brick in the lining of the ladle however, this is subject to the disadvantage that if the porous fire brick fails, the molten metal heat is lost from the ladle at great expense and hazard. It has also been proposed in Canadian Pat. No. 683,737, issued Apr. 7, 1964, to A. Finkel and Sons Company, Chicago, Illinois to include such a refractory gas pervious but molten metal impervious fire brick as a part of the bottom portion of the refractory sleeve in the aforesaid stopper rod assembly with a pipe for the gas extending centrally down thestopper rod assembly to the fire brick. However,- this modification adds considerably to the cost of the stopper as well as weakening it.

The present invention provides a stopper rod assembly which substantially avoids the aforesaid disadvantages, is cheap and simple to install, provides good control over the precise flow of molten metal through the teaming aperture and is readily susceptible to modification for the introduction of purging inert gas into and through the base of the ladle.

It has now been found that by replacing the aforesaid stopper rod assembly by a stopper means comprising a neck dimensioned to extend through the teaming aperture with a gap therebetween, an enlarged head attached to one end of the neck adapted to close'the teaming aperture in theclosed position of the stopper means and a dispenser attached to the other end of the neck having channels extending therethrough generally axially thereof, the channels axially converging to a point remote from said neck such that when the stopper means is located with the neck extending through the apertures, said head is located in the ladle and the dispenser beneath the ladle. The aperture can be opened and closed by vertical movement of the stopper means to seat and unseat the head on the aperture and flow of metal through the aperture in the open position of the stopper means is controlled closely by the dimensions of the gap between the neck and the side wall of the aperture and also the dispenser, which desirably provides lamellar flow of the metal from the dispenser.

According to the present invention, therefore, there is provided a stopper means for use in controlling the flow of molten metal through the teaming aperture of a bottom pouring ladle and movable between a closed position and an open position when in said aperture comprising a neck of heat resistant material dimensioned to extend through the teaming aperture of the ladle with a gap therebetween, an enlarged head of heat resistant material attached to one end of said neck adapted to close the teaming aperture in the closed position of the stopper means and a dispenser attached to the other end of the neck having channels extending therethrough in a direction generally axially of said neck, said channels converging to a point remote from said neck, whereby when said stopper means is located in said aperture said head is located in said ladle and said dispenser is located beneath said ladle.

The present invention also provides in a bottom pouring ladle for use in casting molten metal contained therein, said ladle including a teaming aperture for said molten metal in the base thereof and stopper means movable between an open position in which the molten metal may flow through said aperture and a closed position in which said flow is prevented, the improvement in which said stopper means comprises a neck 'of heat resistant material extendingthrough and spaced from the walls of said aperture to provide a gap therebetween, an enlarged head of heat resistant material attached to one end of said neck and disposed within the ladle, said head being adapted to close said aperture in the closed position of said stopper means and a dispenser of heat resistant material attached to the other end of said neck and disposed beneath the base of said ladle, said dispenser having generally vertically disposed. downwardly converging channels extending therethrough whereby to control the flow of molten metal passing through said aperture and means disposed externally of said ladle for releasably raising said stopper means from said closed position in which said head closes said aperture to said open position in which said head is vertically spaced from said aperture.

In the ladle according to the present invention, the teeming aperture is desirably defined by a nozzle which takes the form of a cylinder of heat resistant material, such as fire clay, which is fixedly mounted in the aperture suitably by means of a nozzle plate attached to the bottom of the ladle shell the nozzle being also retained in position by a fire resistant cement. The cylindrical pipe has the upper end thereof adapted to provide a seat for the enlarged head of the stopper means and is suitably of a concave configuration with the head of the stopper means preferably having a paraboloid or conical configuration. It is critical that the seating of the head on the upper end of the cylindrical pipe provides a good seal when the stopper means is in the closed position. To facilitate this, the head is suitably made of a fire resistant 'material such as a clay-graphite mixture (plumbego) and is capable of a small amount of plastic deformation to provide such a seat.

in order to protect the underneath of the ladle shell which is normally formed of steel including the nozzle plate, from deterioration due to heat radiation from the molten metal passing through the nozzle, the ladle desirably has a shroud attached to the base thereof which shroud is desirably conically shaped and is coaxial with the nozzle, the shroud being made of heat resistant material such as fire clay.

The dispenser of the stopper means has a plurality of channels extending therethrough which are generally axially directed with respect to the neck and converge to a point remote from the neck. The dispenser of such configuration thus collects the molten metal passing through the gap between the neck and the nozzle, the size of which is also preferably dimensioned to provide for lamellar flow of the molten metal, controls the flow thereof by means of the channels into the casting molds and preferably provides for a converging lamellar flow of the molten metal into the casting molds. The dispenser may be cast in one piece but preferably is cast in two portions, a central portion which is attached to the neck and has grooves extending longitudinally thereof on the outside surface thereof and a shroud portion in which the central portion seats whereby the grooves form with the shroud portion the aforesaid channels. By means of the two part dispenser it is found that the erosion of the channels in the dispenser, which is suitably made ,of a zirconia, is substantially reduced and further the stopper means may be raised from the closed position by raising the shroud portion of the dispenser and lowered to the closed position by lowering the shroud portion of the dispender, the head being seated in the nozzle under the action of gravity and also the pressure of the head of metal in the ladle. The shroud portion is suitably raised and lowered by mechanically or pneumatically desirably using a yoke which encompasses the shroud portion and applies a concentric vertical lifting force to the stopper means. The shroud and yoke may be suitable cast in one casting for ease of maintenance. The two part dispenser according to the preferred embodiment of the present invention is simple and cheap to cast and the channels can be more accurately made. The two part dispenser also allows for ease of installation of the stopper means in the ladle and helps reduce tensile loads on the neck. The grooves on the outside surface of the central portion are suitably elliptical or semi-elliptical to provide for lamellar flow and reduction in erosion of the grooves during the flow of metal therethrough. The central portion is preferably in the shape of a truncated cone, the shroud portion also being conical with a similar cone angle. More preferably the central portion is in the form of a pair of truncated cones joined at the base, one of the truncated cones having a larger cone angle and the central portion is attached to the neck through the larger conical angle of the truncated cone. The second cone by which the central portion is attached to the neck aids in the flow of metal through the dispenser by dispensing the molten metal outwardly to the channels in the dispenser. The conical shroud portion is suitably of greater length than the central portion and is disposed around the central portion such that it extends above the central portion to provide a reservoir for any excess molten metal due to the greater flow of molten metal from the ladle through the gap between the neck and the nozzle than through the channels of the dispenser. The shroud portion is suitably provided with an overflowv pipe to allow any excess molten metal flow in excess of that which can be accommodated by the reservoir to flow out from the stopper means directly into the casting mold. This permits optimum groove size in the central portion for good stream control and constant pouring rate and any errors such as could occur during opening of the teaming aperture are harmlessly absorbed by the overflow spout. Further the reservoir allows stream additions, such as aluminum wire feeding, to be conveniently made by simply adding them to the reservoir in the top of the conical shroud. the bottom of the conical shroud forming the dispenser may have attached thereto a pour stream shroud which takes the form of a refractory pipe which shrouds the stream of molten metal exiting from the bottom of the dispenser.

When it is desired to purge the pouring stream exiting from the stopper means this may be conveniently achieved with uniform and efficient addition of the gas by having the gas pass through the vortex at the lower end of the dispenser. At this point the gas enters the converging center of the molten metal streams from the channels. Suitably this is achieved by a pipe extending at least partially centrally down the central portion and connects with a pipe extending through the shroud portion connectable to the source of purging gas. Alignment of the pipe in the shroud with the pipe in the central portion is required but this is relatively simple to achieve. With the unitary dispenser the passage of the purging gas is even simpler as there is no alignment achieved by casting or screwing a plug of heat resistant gas pervious but molten metal impervious material into the top of the stopper head 'with a hollow passage through the geometric center of the stopper means and a pressure fitting is suitably attached to the bottom of the dispenser whereby the gas such as argon, may be purged into the ladle when the pressure applied is greater than the head of molten metal in the ladle. It will be noted that during bubbling of the gas the force of the pressure when the gas is released from the plug pushes the head more firmly into the seat of the nozzle which is desirable.

The head, dispenser and neck of .the stopper means of the present invention may be cast in a single casting with no metallic rod or pipe in the middle to hold the parts together. In this case the nozzle would have to be placed in between the head and dispenser before casting or it will have to be split in an interlocking manner. A bore would still be made in the center of the stopper means for gas purging requirements. Preferably however, the dispenser is made separable from the neck and is also adjustable with respect to the neck which aids in ensuring a vertical concentric lift to the neck and the head when the stopper means is lifted by means of the yoke means via the dispenser particularly the shroud portion of the dispenser.

When a highly dispersed pouring stream is desired such as for vacuum pouring the dispenser may have one or more channels in it for more stream separation and the angle of convergence can be decreased for better stream separation during-vacuum teaming.

The only requirement regarding the lifting means is that concentric lifting forces be applied to the outer circumference of the conical shroudportion.

The present invention will be further illustrated by way of the accompanying drawing in which:

FIG. 1 is a diagramizationpartly broken away and partially in section of a bottom'pouring ladle including the stopper means in accordance with a preferred embodiment of the present invention;

FIG. 2 is a plan detail of the dispenser of the stopper means of FIG. 1;

FIG. 3 is a sectional detail of the stopper means FIG. 1 including means for'introducing gas into the ladles through the stopper;

FIG. 4 is a sectional detail of the dispenser of FIG. 1 including means for injecting purging gas into the molten metal stream exiting from the dispenser, and for shrouding the stream; and

FIG. 5 is a perspective view of the unitary dispenser for use in the stopper means of FIG. 1.

Referring to FIGS. 1 to 3 of the accompanying drawings, a bottom pouring ladle has a steel shell 1 lined with refractory brick 2 and has a teaming aperture 3 in the base thereof for bottom pouring of molten steel, the aperture 3 including a'ram well 4. The aperture 3 is defined by a nozzle 5 in the form of a refractory cylinder which is held in position by a nozzle plate 6 bolted onto the bottom of the shell 1 and cemented in position by refractory cement 7. In order to reduce deterioration of the nozzle plate 6 a conical shroud 8 of a refractory material is attached to the base of the ladle beneath the plate 6. Flow of molten metal through the aperture 3 is controlled by movement of. the stopper 9 which stopper 9 consists of a head 10 formed of a slightly deformable heat resistant material, a neck 1 1 of refractory material and a dispenser 12 of refractory material. The

.a similar conical angle asthe central portion 13 such that the grooves 14 form with the shroud portion 15 channels through which the molten steel must flow as it exits through the aperture 3,in the bottom of the ladle. As is readily apparent from FIGS. 1 to 3, the inside surface of the shroud portion 15 is adapted to be in mating contact with the outside surface of the central portion 13 such that the inside and outside surfaces mate at an interface common to the inside and outside surfaces, the arrangement being such that the laterally spaced vertically converging grooves are at this interface. The conical central portion 13 of the dispenser 12 is attached to the neck 11 through the base thereof which itself is in the-form of a truncated cone so as to disperse the molten metal exiting from the nozzle 5 to the channels in the dispenser 12.

Referring to FIG. 5 the dispenser 12 is of unitary mass and has a plurality of channels 16 extending therethrough for the same purpose as above.

The stopper 9 is raised to its open position by means of a yoke 17 pivoted at one end thereof in a mounting 18 fixedly mounted on the base of the ladle and includes a collar 19 accommodating the shroud portion 15 of the dispenser 12. The stopper 9 is lowered to its closed position under the action of gravity and the ferrostatic'head of metal in the ladle. The raising and lowering of the stopper 9 in the aperture 3 is controlled by means of a control lever 20 which through linkages 21 and 22 causes a slide 23 to move vertically in a barrel- 24 which is pivotablY mounted in a mounting 25 on the side of the ladle. The yoke 17 is attached to the bottom of the slide 23 via a corrector bar 26. The extent of movement of the slide 23 in the barrel 24 is determined by the length of the linkage 22 between the linkage 21 and the fixed bracket 27 on thebarrel 24. To provide for a true vertical lift of the stopper. 9 in the aperture 3, the direction of lift can be adjusted by adjusting the vertical alignment of the barrel 24 and this is achieved by means of screw 28 which is turned by wheel 29 on

bail sockets

30 and 31 in fixed

mountings

32 and 33 on the ladle and barrel 24 respectively. Referring to FIG. 3 in order to introduce gases into the molten metal in the ladle the head 10 is provided with a porous plug 35 which is pervious to the flow of gas but impervious to the flow of molten metal therethrough. Gases pass through the porous plug 35 via a conduit 36 extending longitudinally of the stopper 9 from a flexible hose 37 which is detachably attached to the conduit 36 via an adapter 38.

The shroud portion 15 is desirably longer than the conical central portion 13 of the dispenser 12 to provide a reservoir 39 for excess molten metal passing out of the aperture 3 in the ladel which could not be as rapidly disposed of through the channels in the dispenser 12. This reservoir 39 is suitably provided with an overflow pipe 40 through which passes any metal overflow from the reservoir 39 which overflow is directed into the casting mold disposed beneath the pouring ladle.

Referring to FIG. 4 the bottom of the shroud portion may be provided with a pour stream shroud 41 to protect the molten metal exiting from the dispenser. The pour stream shroud is held in position by the yoke 17 via extensions 50 on the collar 19 which coperate with lip 51 on the shroud 41. The dispenser 12 may also be provided wih a pipe 42 which extends axially of the central portion 13 thereof to direct a purging stream of gas 43 downwardly in to the stream of molten metal exiting from the dispenser 12. The pipe 42 directs the gas into the vortex at the base of the central portion 13 of the dispenser l2. THe pipe 42 is provided with gas from a flexible hose 44 connected by an adapter 45 to a horizontal bore 46 extending through both the shroud portion 15 and the central portion 13 of the dispenser l2 and communicating with the pipe 42.

We claim:

1. In a bottom pouring ladle for use in casting molten metal contained therein said ladle including a teaming aperture for said metal in the base thereof and stopper means movable between an open position in which the molten metal may flow through said aperture and a closed position in which said flow is prevented, the improvement in which said stopper means comprises a neck of heat resistant material extending through and spaced from the walls of said aperture to provide a gap therebetween, an enlarged head of heat resistant material attached to one end of said neck and disposed within said ladle, said head being adapted to close said aperture in the closed position of said stopper means and a dispenser of heat resistant material attached to the other end of said neck and disposed beneath the base of said ladle said dispenser having generally vertically disposed downwardly converging channels extending therethrough whereby to control the flow of molten metal passing through said aperture and means disposed externally of said ladle for releasably raising said stopper means from said closed position in which said head closes said aperture to said open position in which said head is vertically spaced from said aperture, said dispenser comprising a central portion in the form of a truncated cone attached to the neck from the base of said cone and having laterally spaced vertically converging grooves on the outside surface thereof and a separable shroud portion having a conical shape with a conical angle substantially the same as that of the cone and adapted when in contact with said central portion to form with said grooves the channels of said dispenser.

2. A device as claimed in claim 1 in which said aperture is defined by a cylindrical refractory pipe fixedly mounted in said base, the upper end of said pipe being shaped to provide a seat for said head in the closed position of said stopper means.

3. A device as claimed in claim 2 in which the upper end of said pipe has a concave surface for seating said head.

4. A device as claimed in claim 1 in which the dispenser is fixedly attached to the neck.

5. A device as claimed in claim 1 in which said dispenser is separably attached to said neck and angularly adjustable with respect thereto.

6. A device as claimed in claim 1 in which said raising means is arranged to raise said stopper means through said shroud portion of said dispenser.

7. A device as claimed in claim 1 in which the central portion of the dispenser comprises a double truncated cone attached base to base one of said cones having a larger conical angle than the other, the central portion being attached to the neck from said truncated cone having the larger conical angle, said shroud being conically shaped with a conical angle the same as that of the cone with the smaller conical angle.

8. A device as claimed in claim 1 in which the shroud portion is longer than the central portion and extends beyond the top surface of the central portion to provide a reservoir for molten metal passing through the gap between the neck and the walls of the aperture.

9. A device as claimed in claim 8 in which the shroud portion has an overflow pipe extending therethrough into said reservoir.

10. A device as claimed in claim 1 in which the head includes a plug therein of porous refractory material capable of allowing gas to pass therethrough but preventing molten metal passing therethrough, said stopper means including pipe means extending therethrough to said plug to allow to be passed under pressure to said plug through said dispenser neck and head.

11. A device as claimed in claim 1 including a shroud of heat resistant material attached to the outside surface of the base of the ladle arranged to be disposed around said aperture and adapted to protect the base of said ladle from heat generated by said molten metal passing through said aperture.

12. A device as claimed in claim 1 including conduit means extending from the side of said dispenser through said dispenser to substantially the center of the base of said dispenser for the introduction of purging gas from the side of said dispenser into the stream of molten metal passing from said dispenser.

13. A device as claimed in claim 1 including a pouring stream shroud attached to the base of the dispenser.

14. A device as claimed in claim 1 in which the dispenser consists of a single part.

15. A stopper means for use in controlling the flow of molten metal through the teaming aperture of a bottom pouring ladle and movable between a closed and opened position when in said aperture comprising a neck of heat resistant material dimensioned to extend through the teaming aperture of ,the ladle with a gap therebetween and an enlarged head of heat resistant material attached to one end of said neck adapted to close the teaming aperture in the closed position of said stopper means and a dispenser of heat resistant material attached to the other end of said neck having channels extending therethrough in a direction generally axially of said neck, said channels converging to a point remote from said neck whereby when said stopper means is located in said aperture, said head is located in said ladle and said dispenser is located beneath said ladle, said dispenser comprising a central portion in the form of a truncated cone attached to the neck from the base of said cone and having laterally spaced vertically converging grooves on the outside surface thereof and a separable shroud portion having a conical shape with a conical angle substantially the same as that of the cone and adapted when in contact with said central portion to form with said grooves the channels of said dispenser.

16. A stopper means as claimed in claim 15 including a cylindrical refractory pipe disposed around said neck portion to define said teaming aperture in said ladle.

117. A stopper means as' claimed in claim in which the dispenser is fixedly attached to the neck.

18. A stopper means as claimed in claim 15 in which said dispenser is separably attached to said neck and angularly adjustable with respect thereto.

19. A stopper means as claimed in claim 15 in which the central portion of the dispenser comprises a double truncated cone attached base to base, one of said cones having a larger conical angle than the other, the central portion beingattached to the neck from said truncated cone having the larger conical angle, said shroud being conically shaped with a conical angle the same as that of the cone with the smaller conical angle.

20. A stopper means as claimed in claim 15 in which the shroud portion is longer than the central portion and extends beyond the top surface of the central portion to provide a reservoir for molten metal passing through the gap between the neck and the walls of the aperture. v

21. A stopper means as claimed in claim in which the shroud portion has an overflow pipe extending therethrough into said reservoir.

22. A stopper means as claimed in claim 15 in which the head includes a plug therein of porous refractory material capable of allowing gas to pass therethrough but preventing molten metal passing therethrough, said stopper means including pipe means extending therethrough to said plug to allow gas to be passed under pressure to said plug throughsaid dispenser neck and head. 23. A stopper means as claimed in claim 15 including conduit means extending from the side of said dispenser through said dispenser to substantially the center of the base of said dispenser for the introduction of purging gas from the side of said dispenser into the stream of molten metal passing from said dispenser.

24. .In a bottom pouring ladle for use in casting molten metal contained therein said ladle including a teaming aperture for said metal in the base thereof and stopper means movable between an open position in which the molten metal may flow through said aperture and a closed position in which said flow is prevented, the improvement in which said stopper means comprises a neck of heat resistant material extending through and spaced from the walls of said aperture to provide a gap therebetween, an enlarged head of heat resistant material attached to one end of said neck and disposed within said ladle, said head being adapted to close said aperture in the closed position of said stopper means and a dispenser of heat resistant material attached to the other end of said neck and disposed beneath the base of said ladle said dispenser having generally vertically disposed downwardly converging channels extending therethrough whereby to control the flow of molten metal passing through said aperture and means disposed externally of said ladle for releasably raising said stopper means from said closed position in which said head closes said aperture to said open position in which said head is vertically spaced from said aperture, said dispenser comprising a central portion in the form of a truncated cone attached to the neck from the base of said cone and a separable shroud portion having a conical shape with a conical angle substantially the same as that of the cone, the inside surface of said shroud portion being adapted to be in mating contact with the outside surface of said central portion such that the coacting surfaces of said inside and outside surfaces define laterally spaced vertically converging passageways to provide said channels in said dispenser when the inside surface of said shroud portion is in mating contact wih the outside surface of said central portion.

25. A stopper means for use in controlling the flow of molten metal through the teaming aperture of a bottom pouring ladle and movable between a closed and opened position when in said aperture comprising a neck of heat resistant material dimensioned to extend through the teaming aperture of the ladle with a gap therebetween and an enlarged head of heat resistant material attached to one end' of said neck adapted to close the teaming aperture in the closed position of said stopper means and a dispenser of heat resistant material attached to the other end of said neck having channels extending therethrough in a direction generally ax ially of said neck, said channels converging to a point remote from said neck whereby when said stopper means is located in said aperture, said head is located in said ladle and said dispenser is located beneath said ladle, said dispenser comprising a central portion in the form of a truncated cone attached to the neck from the base of said cone and a separable shroud portion having a conical shape with a conical angle substantially the same as that of the cone; the inside surface of said shroud portion being adapted to be in mating contact with the outside surface of said central portion such that the coacting surfaces of said inside and outside surfaces define laterally spaced vertically converging passageways to provide said channels in said dispenser when the inside surface of said shroud portion is in mating contact with the outside surface of said central portion. =0 #0 =t= =0

Claims

10. A device as claimed in claim 1 in which the head includes a plug therein of porous refractory material capable of allowing gas to pass therethrough but preventing molten metal passing therethrough, said stopper means including pipe means extending therethrough to said plug to allow gas to be passed under pressure to said plug through said dispenser neck and head.

15. A stopper means for use in controlling the flow of molten metal through the teaming aperture of a bottom pouring ladle and movable between a closed and opened position when in said aperture comprising a neck of heat resistant material dimensioned to extend through the teaming aperture of the ladle with a gap therebetween and an enlarged head of heat resistant material attached to one end of said neck adapted to close the teaming aperture in the closed position of said stopper means and a dispenser of heat resistant material attached to the other end of said neck having channels extending therethrough in a direction generally axially of said neck, said channels converging to a point remote from said neck whereby when said stopper means is located in said aperture, said head is located in said ladle and said dispenser is located beneath said ladle, said dispenser comprising a central portion in the form of a truncated cone attached to the neck from the base of said cone and having laterally spaced vertically converging grooves on the outside surface thereof and a separable shroud portion having a conical shape with a conical angle substantially the same as that of the cone and adapted when in contact with said central portion to form with said grooves the channels of said dispenser.

17. A stopper means as claimed in claim 15 in which the dispenser is fixedly attached to the neck.

19. A stopper means as claimed in claim 15 in which the central portion of the dispenser comprises a double truncated cone attached base to base, one of said cones having a larger conical angle than the other, the central portion being attached to the neck from said truncated cone having the larger conical angle, said shroud being conically shaped with a conical angle the same as that of the cone with the smaller conical angle.

20. A stopper means as claimed in claim 15 in which the shroud portion is longer than the central portion and extends beyond the top surface of the central portion to provide a reservoir for molten metal passing through the gap between the neck and the walls of the aperture.

21. A stopper means as claimed in claim 20 in which the shroud portion has an overflow pipe extending therethrough into said reservoir.

22. A stopper means as claimed in claim 15 in which the head includes a plug therein of porous refractory material capable of allowing gas to pass therethrough but preventing molten metal passing therethrough, said stopper means including pipe means extending therethrough to said plug to allow gas to be passed under pressure to said plug through said dispenser neck and head.

23. A stopper means as claimed in claim 15 including conduit means extending from the side of said dispenser through said dispenser to substantially the center of the base of said dispenser for the introduction of purging gas from the side of said dispenser into the stream of molten metal passing from said dispenser.

24. In a bottom pouring ladle for use in casting molten metal contained therein said ladle including a teaming aperture for said metal in the base thereof and stopper means movable between an open position in which the molten metal may flow through said aperture and a closed position in which said flow is prevented, the improvement in which said stopper means comprises a neck of heat resistant material extending through and spaced from the walls of said aperture to provide a gap therebetween, an enlarged head of heat resistant material attached to one end of said neck and disposed within said ladle, said head being adapted to close said apErture in the closed position of said stopper means and a dispenser of heat resistant material attached to the other end of said neck and disposed beneath the base of said ladle said dispenser having generally vertically disposed downwardly converging channels extending therethrough whereby to control the flow of molten metal passing through said aperture and means disposed externally of said ladle for releasably raising said stopper means from said closed position in which said head closes said aperture to said open position in which said head is vertically spaced from said aperture, said dispenser comprising a central portion in the form of a truncated cone attached to the neck from the base of said cone and a separable shroud portion having a conical shape with a conical angle substantially the same as that of the cone, the inside surface of said shroud portion being adapted to be in mating contact with the outside surface of said central portion such that the coacting surfaces of said inside and outside surfaces define laterally spaced vertically converging passageways to provide said channels in said dispenser when the inside surface of said shroud portion is in mating contact wih the outside surface of said central portion.

25. A stopper means for use in controlling the flow of molten metal through the teaming aperture of a bottom pouring ladle and movable between a closed and opened position when in said aperture comprising a neck of heat resistant material dimensioned to extend through the teaming aperture of the ladle with a gap therebetween and an enlarged head of heat resistant material attached to one end of said neck adapted to close the teaming aperture in the closed position of said stopper means and a dispenser of heat resistant material attached to the other end of said neck having channels extending therethrough in a direction generally axially of said neck, said channels converging to a point remote from said neck whereby when said stopper means is located in said aperture, said head is located in said ladle and said dispenser is located beneath said ladle, said dispenser comprising a central portion in the form of a truncated cone attached to the neck from the base of said cone and a separable shroud portion having a conical shape with a conical angle substantially the same as that of the cone; the inside surface of said shroud portion being adapted to be in mating contact with the outside surface of said central portion such that the coacting surfaces of said inside and outside surfaces define laterally spaced vertically converging passageways to provide said channels in said dispenser when the inside surface of said shroud portion is in mating contact with the outside surface of said central portion.