CA2014767A1 - Metal pouring apparatus - Google Patents
Metal pouring apparatusInfo
- Publication number
- CA2014767A1 CA2014767A1 CA002014767A CA2014767A CA2014767A1 CA 2014767 A1 CA2014767 A1 CA 2014767A1 CA 002014767 A CA002014767 A CA 002014767A CA 2014767 A CA2014767 A CA 2014767A CA 2014767 A1 CA2014767 A1 CA 2014767A1
- Authority
- CA
- Canada
- Prior art keywords
- duct
- valve member
- enlargement
- exit opening
- melt
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D41/00—Casting melt-holding vessels, e.g. ladles, tundishes, cups or the like
- B22D41/14—Closures
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Lift Valve (AREA)
- Furnace Charging Or Discharging (AREA)
- Flow Control (AREA)
Abstract
Abstract:
"IMPROVEMENTS IN METAL POURING APPARATUS"
Teeming control apparatus comprises an outlet duct installable e.g. in a tundish and providing at least one exit opening. Movable in the duct is a valve member having an enlargement at one end cooperable with a valve seat at the mouth or inlet end of the duct, to open or close the duct to entry of melt from the tundish. The valve member is configured at its other end so as to vary the effective size of the exit opening(s) and thereby provide control over the teeming flow rate from the apparatus.
"IMPROVEMENTS IN METAL POURING APPARATUS"
Teeming control apparatus comprises an outlet duct installable e.g. in a tundish and providing at least one exit opening. Movable in the duct is a valve member having an enlargement at one end cooperable with a valve seat at the mouth or inlet end of the duct, to open or close the duct to entry of melt from the tundish. The valve member is configured at its other end so as to vary the effective size of the exit opening(s) and thereby provide control over the teeming flow rate from the apparatus.
Description
6~
"IMPROVEMENTS IN M~TAL POURING APPARATUS"
This invention relates to improvements in metal pouring apparatu~, and more particularly to improve-ments applicable to the control of pouring or teeming of molten metal along a duct or spout rrom one vessel to another.
More explicitly, the invention concerns a teeming control apparatus by means of which certain operational problems can be reduced or eliminated both at the commencement, and in the course, of teeming.
Metals may be poured from one vessel to another in several ways. One way, to which the present in-vention is not directed, involves tilting the charging vessel to pour the molten metal or melt over a top lip and thus into the receiving vessel. The invention, instead, is concerned with the through-wall teeming, especially the bottom pour teeming technique.
In through-wall and bottom-pour teeming, the melt exits the charging vessel via a pour opening in the wall or bottom, and then traver~eA a duct, spout or nozzle for discharge into the receiving vessel. Teeming is initiated and controlled by a valve arrangement. Two kinds of valve arrangement are well known: they are the stopper rod and the gate valve systems.
~ . :- . . . : -; ~ 2~ 7 .
In principle the ~topp~r rod system ls slmple and effective. It can reliably initiate a teem and - to a degree - can control the teering rate, espec-ially when the stopper rod and pouring opening are in good condition. However, they are subject to the effects of wear, attack and erosion by the molten metal and in part through these efrects proper and accurate control of the teeming rate can be difficult to accomplish. Accurate control is important especially in continuous casting operations.
The gate valve system is better able to control the teeming rate and, in an emergency, may enable teeming to be shut off more quickly. Nevertheless, practical problems can arise. Unlike the stopper rod system, the gate valve system is operative at the bottom or outer end of the pour opening, rather than at its top or inner end. In the absence of 3teps to prevent it, molten metal enters and fills the opening before a teem is initiated. The static metal may well freeze or become pasty there in the pour opening.
This can prevent clean "opening" or commencement of a teem. To combat this problem, a refractory partic-ulate filler may be charged into the pour opening before the charging vessel is filled ~ith molten metal.
25 The filler i9 supposed to discharge ahead of the metal 2~ 17fi7 when the valve is first opened to commence a teem.
ThiQ unfortunately doe~ not always happen. The filler may sinter or develop a hard crust blocking the pour opening. Again, therefore, clean opening may not be attained. Of course, the filler is only useable when teeming is first initiated. If teeming is interrupted for any reason, static metal could freeze in the pour opening before teeming is re-commenced.
Another problem with the gate valve system is the ingress of air into the stream of teeming metal.
This is particularly likely to happen when practising submerged-pour teeming. In this technique, the duct, spout or nozzle has its discharge end immersed in the melt in the receiving vessel. An object of sub-merged pouring is to prevent contamination of themelt by air and this object is obviously defeated if air is drawn into the teeming system by the flowing melt. Not uncommonly, air is sucked in via the juncture between relatively movable valve plates of the gate 20 valve. A solution exists : the valve is surrounded by an atmosphere of inert gas. This is expensive to maintain. Moreover, inert gas instead of air can enter the teeming system and, whilst it might not affect the constitution of the metal, it could still produce 25 metal castings having porosity defects.
Ç
The present invention inter alia aims to overcome the foregoing problems. Thus, it aims to provide teeming apparatus capable of controlling onset, rate and termination of a teem, simply and effectively, to facilitate clean opening of a teem, and to minimiqe or eliminate the possibility of insufflation of air or other gas into the melt stream.
Desirably, the invention is embodied in such a form as will enable it to be installed in a variety of charging vessels. Such vessels can include ladles, degassing vessels and tundishes. Also, desirably, the invention is applicable with a variety of such vessels and other vessels includin2 moulds, partic-ularly continuous casting moulds.
If employed for teeming molten metal into con-tinuous casting moulds, the invention is desirably capable of efficiently distributing the melt into bloom and slab moulds.
According to the present i mention, there is provided metal teeming apparatus comprising a duct or spout having entry and outlet ends respectively formed with a valvs seat and with at least one exit opening, and a valve member in the duct and reciproc-ally movable lengthwise thereof, the valve member having an enlargement at one end to coact with the 2¢~4767 .f . ~
valve seat for blocking or openin~ the duct entry end when the valve member is moved to and Pro, and a configuration at its other end for controlling flow through the exit opening when the enlargement i~ dis-engaged from the seat.
To avoid the risk of air ingress, the duct orspout is an elongate, unitary member devoid of any ~oints between its end~.
Except for the teeming of lo~er melting point metals, the duct or spout and the ~alve member will usually both be made of, or coated with, refractory material resistant to wear and attack by molten metal.
The materials will be selected according to the metal to be teemed and its temperature, as vill be under~tood by the addressee. For teeming ferrou~ melts aluminous material is suitable, for instance in pressed and fired state.
In one embodiment of the invention, t h e d u c t ha~ a convergently tapered outlet end leading to the exit opening and the valve member ha~ a tapered con-figuration at its said other end for coactin~ with the tapered outlet end to control flow. Preferably, the .~ coacting valve member and outlet end provide for pass-age of melt from the duct when the ~alve member has lts enlargecent enBaBed ~ith the val~e seat, ~n use !~
,:, 2~147~;~7 for draining melt from the duct, t h e valve member and outlet end can define an annulan drainage clear-ance. In other words, the arrangesent can be such that the exit opening is not completely cloqed when the enlargement is brought into bl~cking engagement with the valve seat.
In another embodiment of the invention the duct outlet end has at least one exit opening in the wall of the duct for discharging uelt in a lateral direction. Allied with this, the ~alve member is, for example, configured with a second enlargement, at its said other end, the second enlargement being a close fit in the duct outlet end and being cooper-ative with the or each exit opening to control flow therethrough during a control movement of the valve member. Alternatively, the valve mer~er is configured with a second enlargement which is a close fit in the dùct outlet end, and a lateral pro~ection extends from the second enlargement into the or each exit opening ror controlling flow theretbrough. In either case, the or each exit opening can be a longitudinally-extending slot and melt flow therethrough can be controlled by movements of the valve ~ember lengthwise of the duot.
For simplicity in manufacture and in actuation Or the valve member, flow control is ~ained by length-r ~Q~ 67 wise movement~ of the duct. However, the outlet end of the valve member could be confi~ured - e.g. by the provision of a rece~s or channel - so as to con-trol flow through the or each exit op~ning in re~ponse to rotary movements of the valve member.
Embodiments of the invention ~ill now be de-scribed by way of example only with reference to the accompanying drawings, in which:
Fig. 1 is a longitudinal sectional view through teeming control apparatus forming a first embodiment of the invention;
Fig. 2 is a fragmentary perspective view of an outlet end of the first embodiment;
Figs. 3 and 4 are, respectively, a fragmentary longitudinal sectional view and a perspective view of the outlet end of a second embodiment of the in-vention;
Fig. 5 is a longitudinal sectional view of the outlet end of a third embodiment of the invention;
and Fig. 6 is a longitudinal sectional view of `, an alternative inlet or entry end which can be employed ` In any of the embodiments.
Referring to Figs. l and 2 of the drawings, metal teeming apparatus 10 according to the invention ., . - .
:. .
' .
r` ~L'5L76~7 is shown fitted to a metal pouring vessel 11. The ves~el can be a tundish, ladle, degassing veQ~el or other melt-containing vessel used in the metall-urgical industry. Ves~el 11 is shown with a through-wall, bottom-pour opening 12 in which the apparatus i~ mounted. The said apparatu~ is suitably in-stalled, leak-tightly to the bottou wall 14, e.g.
by cementing into place in a refractory lining of the vessel 11.
The apparatus 10 comprises an elongate duct or spout 15 through which melt is discharged into a receiving vessel or mould, not shown, when a valve member 16 in the duct is in an open position, a~
shown. The duct 15 has a melt entry end with a flared or rounded mouth forming a valve seat 18. To co-operate with the seat 18, the valve member 16 has an enlargement 20 at one end. The valve member 16 is reciprocally movable in the duct 15, in a length-wise direction. ~hen moved in one direction, the valve member closes on the valve seat 18 and blocks the duct to entry of melt, and when moved in the other direction to uncover the seat, it opens the duct for teeming of melt from the vessel. For leak-tight sealing of the valve seat 18, the coacting enlargement 20 has suitably rounded shoulders 21.
2~ 7~7 AQ Qhown, the valve member iq lowered and raised, respectively, to close and open the duct to flow of melt.
The duct 15 is a unitary member devoid of joints along it~ length between itQ entry end and its opposite bullet end 22. Joints are avoided to eliminate the risk of insufflation of air during teeming.
The duct 15 has at least one melt exit opening at the outlet end 22. In the embodiment of Figs.
1 and 2, there are two such opening~ 24, diametric-ally opposed. In this example, the openings 24 are formed as a pair of slots. These slot~ extend axially in the wall of the duct, upwardly from the extreme end thereof.
The lower end of the valve menber 16 is con-figured to cooperate with the opening-~ 24 to control flow of melt from the duct after the valve member iq lifted from engagement with the seat 18. To this end, the valve member has a second enlargement 26 at its lower or downstream end. The second enlarge-ment is a close but sliding fit in the outlet end 22 of the duct 15. If the valve nember ic raised and lowered, shorter or longer lengths of the slot-~haped openings 24 are exposed to flow from the 4:~7 duct 15.
It will be observed that the ~econd enlargement 26 has an inclined or arcuate shoulder 28. ItA down-ward and outward inclination assist~ in deflecting melt flowing down the duct in lateral directions out of the exit openings 24.
The two enlargements 20, 26 of the valve member 16 are interconnected by a narrower stem portion 29. The stem portion 29 and duct 15 are dimensioned having regard for the size of the exit openings 24 to afford free passage of melt, at a desired maximum rate.
Since the apparatus 10 is arranged for melt to discharge in diametrically opposed lateral di-rections, it is well suited for feeding melt intoa continuous slab caster mould.
The apparatus 10 can have a different outlet end configuration, as illustrated in Figs. 3 and 4. Again, the apparatus has a duct 10 with two opposed exit openings 24 in the wall thereof, and a valve member 16 with a second enlargement 26 closely fitting the inside of the duct 15. In this case, the enlargement 26 is transversely slotted, at 30, to receive a transverse element 31. The ele-ment 31 projects laterally from the enlargement ':
:
26 forming two lugs or ears 32 ~hich are close,sliding fits in the re~peetive slotted exit openings 24. Each lug 32 has a downwardly-inclined top surface 33 to a~sist in deflecting flowing melt in lateral directions out of the exit openings. The latter have top end surfaces 34 which are sinilarly inclined.
A~ with the previous embodiment, the embodiment of Figs. 3 and 4 affords control of flow from the apparatu 10 depending on the position of the valve member 16 in the duct 15. In a lovermost position, the valve member closes the duct to entry of melt from the vessel. When the valve m~mber is raised, disengaging it from the seat, flow of melt can immed-iately commence. The flow rate from the exit opening~
24 again decreases with raising of the valve member 16, as the effective size of each opening is progress-ively reduced by the rising lugs 32.
Once more, this embodiment is well quited -for teeminB melt into the mould Or a continuous slab caster.
In both the foregoing embodiments, a lowering of the valve member 16 to engage the valve seat 18 blocks the inflow of melt into the duct 15. At the same time, the exit opening~ 24 are fully opened, thus allowing melt already in the duct to drain 47~
away into a receiving vesQel or mould.
Fig. 5 show~q the outlet end of another embodi-ment of the invention. In this caqe, the outlet end has a form quiting teeming into the mould of a continuous bloom caster. In this embodiment, the duct 15 has a ~ingle exit opening 36. Opening 36 is at the very end of the duct 15 rather than in its 3ide wall. The outlet end portion of the duct is convergingly tapered at 37. The val~e member 15 in this instance does not have a second enlarge-ment. In this case, its stem 29 ha-~ a tapered end portion 38 generally matching the taper of the duct outlet end portion.
It will be appreciated that in this embodiment the configuration of the valve member at its lower end portion 38 is such as to control flow of melt through the exit opening 36. Raising and lowering movements of the valve member 16 respectively will increase or decrease flow from the opening 36. The discharge flow direction will, of course, be axial in this embodiment.
The embodiment illustrated in Fig. 5 has the valve member 16 and outlet end portion 37 90 con-figured as to allow melt to drain from the duct 15 when the valve member is lowered to engage the 17tS'7 f valve seat 18. To this end, the valve member is undersized relative to the adjacent ~all of the duct so as to leave an annular drainage clearance 39 therebetween when the valve member 16 is engaged with the seat.
In Fig. 6 is shown an alternative form of inlet end which may be incorporated in any embodiment of the invention. The valve member 16 has an enlargement 20 similar to that shown in Fig. 1, but the duct 15 has a flared mouth or trumpet 40. The trumpet facilitates installation of the duct 15 in a frustoconical well element 42 in the refractory lining ~4 of the vessel 11. A similar form of installation can be adopted for the Fig. 1 arrangement, as indicated at the right hand side of this Figure. The enlargement 20 and trumpet coact as before for blocking the duct to entry of melt from the vessel 11.
The duct and valve member can be made of any material able to withstand the temperature and effects of the melt. For controlled teeming of ferrous metals, they can be made e.g. of aluminous refractory, for instance in pressed and fired form.
Movement of the valve member to open and close tho duct to melt, and to control flo~ rate therefrom, .
- 14 ~
can be controlled by any convenient drive means D.
Such drive means D could comprise mechanical, electrical pneumatic or hydraulic actuators. The dr~ve means would ordinarily be linked in any suitable way to the upper end of the valve member 16. The linkage would thus have to extend through the melt and must be able to withstand it, therefore. Accordingly, the linkage could include a control rod made of, or coated with, a refractory material.
The drive means could, in principle, be connected to the other end of the valve member, via the terminal end of the duct 15. This would be satisfactory, for example, if the apparatus were installed in a side wall of the vessel, adjacent its base, and if the duct had an exit opening disposed in the side ~all of the duct, facing downwardly.
In each of the foregoing embodiments, control movements of the valve member 16 for controlling flow rate are lengthwi3e movements. As indicated hereinbefore, rotary control movements would be a posslbility if the outlet end configuration of the apparatus were adapted in ways which Yill be apparent to the addressee.
Beneficially, the said drive means is arranged to displace the valve member 16 continuously during a teem by imparting a reciprocal, vibratory or oscillatory -^ 2 motion to it. By havin~ relative motion between the valve member 16 and the duct 15, accumulation or accretion of any inclusions in the melt between the duct and valve member ~ill be hindered. The motion imparted to the valve member can be of small amplitude.
Of course, if more convenient, the continuous motion imparted to the valve member can be derived from a separate drive means (~').
It will be appreciated from the preceding description that the disclosed embodiments provide no route by which air - or any other gas - may be sucked into the apparatus lO by the flowing melt. Further, the possibility of melt residing in the duct 15 and possibly blocking it has been avoided, and the need for particulate fillers has been eliminated. Flow of melt can be terminated rapidly in an emergency and good control over the teeming flow rate is attainable.
Moreover, the apparatus of this invention is of a desirably simple construction which will facilitate manufacture, assembly and servicing.
The component parts, namely the duct and valve member can be economically manufactured. This is beneficial since their service lives will be limited owing to the aggressive environment to which they inevitably are exposed.
~ -f` 2~7~,7 Industrial Applicability The invention is applicable to the controlled teeming, or pouring, of high temperature liquids, in particular molten metals such as stainless steels, from a vessel to a receiver such as a mould. By means of the invention the flow of molten metal can be initiated and terminated, or varied as to the rate of flow. Controlled pouring by means of this invention can facilitate casting operations, for instance in the continuous casting process.
"IMPROVEMENTS IN M~TAL POURING APPARATUS"
This invention relates to improvements in metal pouring apparatu~, and more particularly to improve-ments applicable to the control of pouring or teeming of molten metal along a duct or spout rrom one vessel to another.
More explicitly, the invention concerns a teeming control apparatus by means of which certain operational problems can be reduced or eliminated both at the commencement, and in the course, of teeming.
Metals may be poured from one vessel to another in several ways. One way, to which the present in-vention is not directed, involves tilting the charging vessel to pour the molten metal or melt over a top lip and thus into the receiving vessel. The invention, instead, is concerned with the through-wall teeming, especially the bottom pour teeming technique.
In through-wall and bottom-pour teeming, the melt exits the charging vessel via a pour opening in the wall or bottom, and then traver~eA a duct, spout or nozzle for discharge into the receiving vessel. Teeming is initiated and controlled by a valve arrangement. Two kinds of valve arrangement are well known: they are the stopper rod and the gate valve systems.
~ . :- . . . : -; ~ 2~ 7 .
In principle the ~topp~r rod system ls slmple and effective. It can reliably initiate a teem and - to a degree - can control the teering rate, espec-ially when the stopper rod and pouring opening are in good condition. However, they are subject to the effects of wear, attack and erosion by the molten metal and in part through these efrects proper and accurate control of the teeming rate can be difficult to accomplish. Accurate control is important especially in continuous casting operations.
The gate valve system is better able to control the teeming rate and, in an emergency, may enable teeming to be shut off more quickly. Nevertheless, practical problems can arise. Unlike the stopper rod system, the gate valve system is operative at the bottom or outer end of the pour opening, rather than at its top or inner end. In the absence of 3teps to prevent it, molten metal enters and fills the opening before a teem is initiated. The static metal may well freeze or become pasty there in the pour opening.
This can prevent clean "opening" or commencement of a teem. To combat this problem, a refractory partic-ulate filler may be charged into the pour opening before the charging vessel is filled ~ith molten metal.
25 The filler i9 supposed to discharge ahead of the metal 2~ 17fi7 when the valve is first opened to commence a teem.
ThiQ unfortunately doe~ not always happen. The filler may sinter or develop a hard crust blocking the pour opening. Again, therefore, clean opening may not be attained. Of course, the filler is only useable when teeming is first initiated. If teeming is interrupted for any reason, static metal could freeze in the pour opening before teeming is re-commenced.
Another problem with the gate valve system is the ingress of air into the stream of teeming metal.
This is particularly likely to happen when practising submerged-pour teeming. In this technique, the duct, spout or nozzle has its discharge end immersed in the melt in the receiving vessel. An object of sub-merged pouring is to prevent contamination of themelt by air and this object is obviously defeated if air is drawn into the teeming system by the flowing melt. Not uncommonly, air is sucked in via the juncture between relatively movable valve plates of the gate 20 valve. A solution exists : the valve is surrounded by an atmosphere of inert gas. This is expensive to maintain. Moreover, inert gas instead of air can enter the teeming system and, whilst it might not affect the constitution of the metal, it could still produce 25 metal castings having porosity defects.
Ç
The present invention inter alia aims to overcome the foregoing problems. Thus, it aims to provide teeming apparatus capable of controlling onset, rate and termination of a teem, simply and effectively, to facilitate clean opening of a teem, and to minimiqe or eliminate the possibility of insufflation of air or other gas into the melt stream.
Desirably, the invention is embodied in such a form as will enable it to be installed in a variety of charging vessels. Such vessels can include ladles, degassing vessels and tundishes. Also, desirably, the invention is applicable with a variety of such vessels and other vessels includin2 moulds, partic-ularly continuous casting moulds.
If employed for teeming molten metal into con-tinuous casting moulds, the invention is desirably capable of efficiently distributing the melt into bloom and slab moulds.
According to the present i mention, there is provided metal teeming apparatus comprising a duct or spout having entry and outlet ends respectively formed with a valvs seat and with at least one exit opening, and a valve member in the duct and reciproc-ally movable lengthwise thereof, the valve member having an enlargement at one end to coact with the 2¢~4767 .f . ~
valve seat for blocking or openin~ the duct entry end when the valve member is moved to and Pro, and a configuration at its other end for controlling flow through the exit opening when the enlargement i~ dis-engaged from the seat.
To avoid the risk of air ingress, the duct orspout is an elongate, unitary member devoid of any ~oints between its end~.
Except for the teeming of lo~er melting point metals, the duct or spout and the ~alve member will usually both be made of, or coated with, refractory material resistant to wear and attack by molten metal.
The materials will be selected according to the metal to be teemed and its temperature, as vill be under~tood by the addressee. For teeming ferrou~ melts aluminous material is suitable, for instance in pressed and fired state.
In one embodiment of the invention, t h e d u c t ha~ a convergently tapered outlet end leading to the exit opening and the valve member ha~ a tapered con-figuration at its said other end for coactin~ with the tapered outlet end to control flow. Preferably, the .~ coacting valve member and outlet end provide for pass-age of melt from the duct when the ~alve member has lts enlargecent enBaBed ~ith the val~e seat, ~n use !~
,:, 2~147~;~7 for draining melt from the duct, t h e valve member and outlet end can define an annulan drainage clear-ance. In other words, the arrangesent can be such that the exit opening is not completely cloqed when the enlargement is brought into bl~cking engagement with the valve seat.
In another embodiment of the invention the duct outlet end has at least one exit opening in the wall of the duct for discharging uelt in a lateral direction. Allied with this, the ~alve member is, for example, configured with a second enlargement, at its said other end, the second enlargement being a close fit in the duct outlet end and being cooper-ative with the or each exit opening to control flow therethrough during a control movement of the valve member. Alternatively, the valve mer~er is configured with a second enlargement which is a close fit in the dùct outlet end, and a lateral pro~ection extends from the second enlargement into the or each exit opening ror controlling flow theretbrough. In either case, the or each exit opening can be a longitudinally-extending slot and melt flow therethrough can be controlled by movements of the valve ~ember lengthwise of the duot.
For simplicity in manufacture and in actuation Or the valve member, flow control is ~ained by length-r ~Q~ 67 wise movement~ of the duct. However, the outlet end of the valve member could be confi~ured - e.g. by the provision of a rece~s or channel - so as to con-trol flow through the or each exit op~ning in re~ponse to rotary movements of the valve member.
Embodiments of the invention ~ill now be de-scribed by way of example only with reference to the accompanying drawings, in which:
Fig. 1 is a longitudinal sectional view through teeming control apparatus forming a first embodiment of the invention;
Fig. 2 is a fragmentary perspective view of an outlet end of the first embodiment;
Figs. 3 and 4 are, respectively, a fragmentary longitudinal sectional view and a perspective view of the outlet end of a second embodiment of the in-vention;
Fig. 5 is a longitudinal sectional view of the outlet end of a third embodiment of the invention;
and Fig. 6 is a longitudinal sectional view of `, an alternative inlet or entry end which can be employed ` In any of the embodiments.
Referring to Figs. l and 2 of the drawings, metal teeming apparatus 10 according to the invention ., . - .
:. .
' .
r` ~L'5L76~7 is shown fitted to a metal pouring vessel 11. The ves~el can be a tundish, ladle, degassing veQ~el or other melt-containing vessel used in the metall-urgical industry. Ves~el 11 is shown with a through-wall, bottom-pour opening 12 in which the apparatus i~ mounted. The said apparatu~ is suitably in-stalled, leak-tightly to the bottou wall 14, e.g.
by cementing into place in a refractory lining of the vessel 11.
The apparatus 10 comprises an elongate duct or spout 15 through which melt is discharged into a receiving vessel or mould, not shown, when a valve member 16 in the duct is in an open position, a~
shown. The duct 15 has a melt entry end with a flared or rounded mouth forming a valve seat 18. To co-operate with the seat 18, the valve member 16 has an enlargement 20 at one end. The valve member 16 is reciprocally movable in the duct 15, in a length-wise direction. ~hen moved in one direction, the valve member closes on the valve seat 18 and blocks the duct to entry of melt, and when moved in the other direction to uncover the seat, it opens the duct for teeming of melt from the vessel. For leak-tight sealing of the valve seat 18, the coacting enlargement 20 has suitably rounded shoulders 21.
2~ 7~7 AQ Qhown, the valve member iq lowered and raised, respectively, to close and open the duct to flow of melt.
The duct 15 is a unitary member devoid of joints along it~ length between itQ entry end and its opposite bullet end 22. Joints are avoided to eliminate the risk of insufflation of air during teeming.
The duct 15 has at least one melt exit opening at the outlet end 22. In the embodiment of Figs.
1 and 2, there are two such opening~ 24, diametric-ally opposed. In this example, the openings 24 are formed as a pair of slots. These slot~ extend axially in the wall of the duct, upwardly from the extreme end thereof.
The lower end of the valve menber 16 is con-figured to cooperate with the opening-~ 24 to control flow of melt from the duct after the valve member iq lifted from engagement with the seat 18. To this end, the valve member has a second enlargement 26 at its lower or downstream end. The second enlarge-ment is a close but sliding fit in the outlet end 22 of the duct 15. If the valve nember ic raised and lowered, shorter or longer lengths of the slot-~haped openings 24 are exposed to flow from the 4:~7 duct 15.
It will be observed that the ~econd enlargement 26 has an inclined or arcuate shoulder 28. ItA down-ward and outward inclination assist~ in deflecting melt flowing down the duct in lateral directions out of the exit openings 24.
The two enlargements 20, 26 of the valve member 16 are interconnected by a narrower stem portion 29. The stem portion 29 and duct 15 are dimensioned having regard for the size of the exit openings 24 to afford free passage of melt, at a desired maximum rate.
Since the apparatus 10 is arranged for melt to discharge in diametrically opposed lateral di-rections, it is well suited for feeding melt intoa continuous slab caster mould.
The apparatus 10 can have a different outlet end configuration, as illustrated in Figs. 3 and 4. Again, the apparatus has a duct 10 with two opposed exit openings 24 in the wall thereof, and a valve member 16 with a second enlargement 26 closely fitting the inside of the duct 15. In this case, the enlargement 26 is transversely slotted, at 30, to receive a transverse element 31. The ele-ment 31 projects laterally from the enlargement ':
:
26 forming two lugs or ears 32 ~hich are close,sliding fits in the re~peetive slotted exit openings 24. Each lug 32 has a downwardly-inclined top surface 33 to a~sist in deflecting flowing melt in lateral directions out of the exit openings. The latter have top end surfaces 34 which are sinilarly inclined.
A~ with the previous embodiment, the embodiment of Figs. 3 and 4 affords control of flow from the apparatu 10 depending on the position of the valve member 16 in the duct 15. In a lovermost position, the valve member closes the duct to entry of melt from the vessel. When the valve m~mber is raised, disengaging it from the seat, flow of melt can immed-iately commence. The flow rate from the exit opening~
24 again decreases with raising of the valve member 16, as the effective size of each opening is progress-ively reduced by the rising lugs 32.
Once more, this embodiment is well quited -for teeminB melt into the mould Or a continuous slab caster.
In both the foregoing embodiments, a lowering of the valve member 16 to engage the valve seat 18 blocks the inflow of melt into the duct 15. At the same time, the exit opening~ 24 are fully opened, thus allowing melt already in the duct to drain 47~
away into a receiving vesQel or mould.
Fig. 5 show~q the outlet end of another embodi-ment of the invention. In this caqe, the outlet end has a form quiting teeming into the mould of a continuous bloom caster. In this embodiment, the duct 15 has a ~ingle exit opening 36. Opening 36 is at the very end of the duct 15 rather than in its 3ide wall. The outlet end portion of the duct is convergingly tapered at 37. The val~e member 15 in this instance does not have a second enlarge-ment. In this case, its stem 29 ha-~ a tapered end portion 38 generally matching the taper of the duct outlet end portion.
It will be appreciated that in this embodiment the configuration of the valve member at its lower end portion 38 is such as to control flow of melt through the exit opening 36. Raising and lowering movements of the valve member 16 respectively will increase or decrease flow from the opening 36. The discharge flow direction will, of course, be axial in this embodiment.
The embodiment illustrated in Fig. 5 has the valve member 16 and outlet end portion 37 90 con-figured as to allow melt to drain from the duct 15 when the valve member is lowered to engage the 17tS'7 f valve seat 18. To this end, the valve member is undersized relative to the adjacent ~all of the duct so as to leave an annular drainage clearance 39 therebetween when the valve member 16 is engaged with the seat.
In Fig. 6 is shown an alternative form of inlet end which may be incorporated in any embodiment of the invention. The valve member 16 has an enlargement 20 similar to that shown in Fig. 1, but the duct 15 has a flared mouth or trumpet 40. The trumpet facilitates installation of the duct 15 in a frustoconical well element 42 in the refractory lining ~4 of the vessel 11. A similar form of installation can be adopted for the Fig. 1 arrangement, as indicated at the right hand side of this Figure. The enlargement 20 and trumpet coact as before for blocking the duct to entry of melt from the vessel 11.
The duct and valve member can be made of any material able to withstand the temperature and effects of the melt. For controlled teeming of ferrous metals, they can be made e.g. of aluminous refractory, for instance in pressed and fired form.
Movement of the valve member to open and close tho duct to melt, and to control flo~ rate therefrom, .
- 14 ~
can be controlled by any convenient drive means D.
Such drive means D could comprise mechanical, electrical pneumatic or hydraulic actuators. The dr~ve means would ordinarily be linked in any suitable way to the upper end of the valve member 16. The linkage would thus have to extend through the melt and must be able to withstand it, therefore. Accordingly, the linkage could include a control rod made of, or coated with, a refractory material.
The drive means could, in principle, be connected to the other end of the valve member, via the terminal end of the duct 15. This would be satisfactory, for example, if the apparatus were installed in a side wall of the vessel, adjacent its base, and if the duct had an exit opening disposed in the side ~all of the duct, facing downwardly.
In each of the foregoing embodiments, control movements of the valve member 16 for controlling flow rate are lengthwi3e movements. As indicated hereinbefore, rotary control movements would be a posslbility if the outlet end configuration of the apparatus were adapted in ways which Yill be apparent to the addressee.
Beneficially, the said drive means is arranged to displace the valve member 16 continuously during a teem by imparting a reciprocal, vibratory or oscillatory -^ 2 motion to it. By havin~ relative motion between the valve member 16 and the duct 15, accumulation or accretion of any inclusions in the melt between the duct and valve member ~ill be hindered. The motion imparted to the valve member can be of small amplitude.
Of course, if more convenient, the continuous motion imparted to the valve member can be derived from a separate drive means (~').
It will be appreciated from the preceding description that the disclosed embodiments provide no route by which air - or any other gas - may be sucked into the apparatus lO by the flowing melt. Further, the possibility of melt residing in the duct 15 and possibly blocking it has been avoided, and the need for particulate fillers has been eliminated. Flow of melt can be terminated rapidly in an emergency and good control over the teeming flow rate is attainable.
Moreover, the apparatus of this invention is of a desirably simple construction which will facilitate manufacture, assembly and servicing.
The component parts, namely the duct and valve member can be economically manufactured. This is beneficial since their service lives will be limited owing to the aggressive environment to which they inevitably are exposed.
~ -f` 2~7~,7 Industrial Applicability The invention is applicable to the controlled teeming, or pouring, of high temperature liquids, in particular molten metals such as stainless steels, from a vessel to a receiver such as a mould. By means of the invention the flow of molten metal can be initiated and terminated, or varied as to the rate of flow. Controlled pouring by means of this invention can facilitate casting operations, for instance in the continuous casting process.
Claims (23)
1. Metal teeming apparatus comprising a duct or spout having entry and outlet ends respectively formed with a valve seat and with at least one exit opening, and a valve member in the duct and reciprocally movable lengthwise thereof, the valve member having an enlargement at one end to coact with the valve seat for blocking or opening the duct entry end when the valve member is moved to and fro, and a configuration at its other end for controlling flow through the exit opening when the enlargement is disengaged from the seat.
2. Apparatus according to claim 1, wherein the duct or spout is an elongate, unitary member devoid of joints.
3. Apparatus according to claim 1, wherein the duct or spout and the valve member are both made of refractory materials resistant to wear or attack by molten metal.
4. Apparatus according to claim 1, wherein the duct or spout and the valve member are both coated with refractory materials resistant to wear or attack by molten metal.
5. Apparatus according to claim 1, wherein the valve seat and the enlargement have rounded profiles capable of engaging one with the other to form a melt-tight blocking of the duct.
6. Apparatus according to claim 1, wherein the duct has a convergently tapered outlet end leading to the exit opening and the valve member has a tapered configuration at its said other end for coacting with the tapered outlet end to control flow.
7. Apparatus according to claim 6, wherein the coacting valve member and outlet end provide for passage of melt from the duct when the valve member has its enlargement engaged with the valve seat, in use for draining melt from the duct.
8. Apparatus according to claim 7, wherein the valve member and the outlet end define therebetween an annular drainage clearance when the said enlargement is engaged with the valve seat.
9. Apparatus according to claim 1, wherein the duct outlet end has at least one exit opening in the wall of the duct for discharging melt in a lateral direction.
10. Apparatus according to claim 9, wherein the valve member is configured with a second enlargement, at its said other end, the second enlargement being a close fit in the duct outlet end and being cooperative with said at least one exit opening to control flow therethrough during a control movement of the valve member.
11. Apparatus according to claim 10, wherein the valve member is movable lengthwise of the duct for the flow control movement.
12. Apparatus according to claim 10, wherein the second enlargement has an inclined or arcuate shoulder in use for deflecting melt in a lateral direction out through said at least one exit opening.
13. Apparatus according to claim 9, wherein said at least one exit opening comprises a slot in the duct wall.
14. Apparatus according to claim 13, wherein said slot extends longitudinally of the duct.
15. Apparatus according to claim 9, wherein the valve member is configured with a second enlargement which is a close fit in the duct outlet end, and a lateral projection extends from the second enlargement into said at least one exit opening for controlling flow therethrough.
16. Apparatus according to claim 15, wherein said at least one exit opening is a longitudinally-extending slot and the associated projection is operable to control flow therethrough in response to movements of the valve member lengthwise of the duct.
17. Apparatus according to claim 15, wherein said projection has an inclined surface in use for deflecting melt in a lateral direction out through the associated exit opening.
18. Apparatus according to claim 1, further including drive means connected to the valve member and operative for reciprocating same and for effecting flow control movements thereof.
19. Apparatus according to claim 18, wherein said drive means are operative to maintain the valve member in a state of continual motion when it is in a duct-open position.
20. Apparatus according to claim 19, wherein said means is operative to maintain the valve member in a state of continual motion selected from vibratory, reciprocatory and oscillatory motion.
21. Apparatus according to claim 18, wherein further drive means coupled to the valve member are operative to maintain the valve member in a state of continual motion when it is in a duct-open position.
22. Apparatus according to claim 21, wherein said means is operative to maintain the valve member in a state of continual motion selected from vibratory, reciprocatory and oscillatory motion.
23. A molten metal pouring vessel incorporating metal teeming apparatus according to claim 1.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB898908873A GB8908873D0 (en) | 1989-04-19 | 1989-04-19 | Improvements in metal pouring apparatus |
| GB8908873 | 1989-04-19 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2014767A1 true CA2014767A1 (en) | 1990-10-19 |
Family
ID=10655309
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002014767A Abandoned CA2014767A1 (en) | 1989-04-19 | 1990-04-18 | Metal pouring apparatus |
Country Status (5)
| Country | Link |
|---|---|
| AU (1) | AU5443790A (en) |
| CA (1) | CA2014767A1 (en) |
| GB (1) | GB8908873D0 (en) |
| WO (1) | WO1990012667A2 (en) |
| ZA (1) | ZA902867B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NO20020589A (en) * | 2002-02-06 | 2003-06-30 | Sigmund Rekkedal | Dosing valve with eccentric opener function with power torque for gravity casting of liquid metal |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB917565A (en) * | 1960-05-13 | 1963-02-06 | Didier Werke Ag | Improvements relating to pouring nozzles for liquid metal |
| GB1112819A (en) * | 1964-12-03 | 1968-05-08 | United Steel Companies Ltd | Nozzle and stopper assemblies for the teeming of liquid metal |
| US3511421A (en) * | 1968-04-29 | 1970-05-12 | William H Smith | Stopper and nozzle construction for metal ladles |
| JPS526926B1 (en) * | 1968-11-26 | 1977-02-25 |
-
1989
- 1989-04-19 GB GB898908873A patent/GB8908873D0/en active Pending
-
1990
- 1990-04-17 ZA ZA902867A patent/ZA902867B/en unknown
- 1990-04-18 CA CA002014767A patent/CA2014767A1/en not_active Abandoned
- 1990-04-19 WO PCT/GB1990/000596 patent/WO1990012667A2/en unknown
- 1990-04-19 AU AU54437/90A patent/AU5443790A/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| WO1990012667A2 (en) | 1990-11-01 |
| ZA902867B (en) | 1991-05-29 |
| WO1990012667A3 (en) | 1991-01-10 |
| GB8908873D0 (en) | 1989-06-07 |
| AU5443790A (en) | 1990-11-16 |
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