US20090152778A1 - Stopper Rod - Google Patents
Stopper Rod Download PDFInfo
- Publication number
- US20090152778A1 US20090152778A1 US11/921,090 US92109006A US2009152778A1 US 20090152778 A1 US20090152778 A1 US 20090152778A1 US 92109006 A US92109006 A US 92109006A US 2009152778 A1 US2009152778 A1 US 2009152778A1
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- US
- United States
- Prior art keywords
- stopper rod
- sealing means
- carrier element
- insert
- rod body
- 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
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Classifications
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- 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
- B22D41/16—Closures stopper-rod type, i.e. a stopper-rod being positioned downwardly through the vessel and the metal therein, for selective registry with the pouring opening
- B22D41/18—Stopper-rods therefor
-
- 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
- B22D41/16—Closures stopper-rod type, i.e. a stopper-rod being positioned downwardly through the vessel and the metal therein, for selective registry with the pouring opening
- B22D41/18—Stopper-rods therefor
- B22D41/186—Stopper-rods therefor with means for injecting a fluid into the melt
Definitions
- This invention relates to a stopper rod for controlling the flow of molten metal, for example from a vessel, such as a tundish, to a mould, and more preferably, to a stopper rod for supplying an inert gas to the melt in the vessel.
- Such a stopper rod is well known, it being moved in the direction of its longitudinal axis by a lifting device external to the vessel in which the stopper rod is disposed, so that an outlet opening in the base of the vessel, into which the stopper rod fits at its lowest position, shutting it off completely, is opened either more or less. The flow of metal through the opening is thus controllable.
- An object of the invention is to provide a stopper rod in an improved form.
- a stopper rod comprising a refractory material stopper rod body having an internal passageway extending from a first end of the body towards a second end thereof, a metal carrier element having one of its ends received in said passageway, the carrier element having a laterally enlarged portion received in a laterally enlarged portion of the passageway, which passageway portion defines a seating surface, and sealing means between said seating surface and an underside of the laterally enlarged portion of the carrier element, wherein an insert is threadedly engaged with one of the carrier element and the stopper rod body at a position above said laterally enlarged portion of the carrier element, with further sealing means being disposed between said insert and the carrier element.
- the carrier element which serves, in use, to connect the stopper rod to a lifting device, has a gas supply passage extending therethrough.
- the sealing means is a graphoil seal.
- the insert is threadedly engaged with the carrier element.
- the further sealing means is a packing gland seal.
- the insert is threadedly engaged with the stopper rod body.
- the further sealing means is a graphoil seal, which is preferably thicker than the graphoil seal forming said sealing means.
- the insert is threadedly engaged with a ceramic insert which is preferably pressed into the stopper rod to form part thereof.
- the sealing means is disposed between complementary frustoconical surfaces respectively of the enlarged portion of the carrier element and said seating surface. Until the stopper rod heats up, the sealing means is compressed between the carrier element and the stopper rod body and provides a gas-tight seal therebetween. As the stopper rod heats up, gas tightness is maintained by the further sealing means, even if the seal provided by the sealing means starts to leak due to the expansion of the metal carrier element.
- the insert is engaged with a complementary thread on the carrier element.
- the insert is screwed down tightly on the further sealing means to effect radial sealing to the inner annular wall of the passageway of the stopper rod body.
- the whole assembly simply slides up fractionally, but the force on the further sealing means, and hence the gas-tightness, is maintained.
- the insert is a collar, which can be metallic or ceramic, threadedly engaged with a corresponding thread at an upper inner surface of the internal passageway in the stopper rod body.
- the thread can be pressed in the stopper rod body passageway, or provided by a pressed-in ceramic insert forming part of the stopper rod body.
- the insert is in the form of a nut screw-threadedly engaged on the carrier element, which nut, when tightened, effects axial compression of said further sealing means, resulting in sealing between the stopper rod body and the carrier element.
- the nut preferably effects axial compression of said further sealing means through the intermediary of a washer.
- the washer is located around the carrier element at one end of the stopper rod body.
- the washer is larger than the further sealing means, and particularly of larger diameter than the diameter of the upper end of the internal passageway in the stopper rod body, in which upper end the further sealing means is received.
- the further sealing means is preferably two graphoil seals which stand proud of said upper end of the stopper rod body when the nut is untightened, and are axially compressed into said upper end of the passageway when the nut is tightened onto the washer to cause the washer axially to compress the graphoil seals.
- FIG. 1 is a schematic side view of the interior of the upper end of a prior art stopper rod
- FIG. 2 is a view like FIG. 1 , for a stopper rod of the invention.
- FIG. 3 is a similar view to FIG. 2 , for a stopper rod according to a further embodiment of the invention
- FIG. 4 is a view like FIG. 3 of a stopper rod according to a still further embodiment of the invention.
- FIG. 5 is a split schematic cross-sectional view of the upper end of a stopper rod of the invention, the left half showing sealing means uncompressed, and the right half showing the sealing means compressed.
- FIG. 1 schematically shows the upper end of a prior art stopper rod 10 having a conventional stopper rod body 11 of refractory/ceramic material.
- a circular cross-section longitudinal bore 12 Extending centrally, axially within the stopper rod body 11 from the upper end thereof is a circular cross-section longitudinal bore 12 .
- Extending downwards from this surface 13 is a constant diameter circular cross-section part, which leads to a radially enlarged portion of the bore in which is secured a ceramic insert 14 , the insert being secured to the stopper rod body 11 .
- the insert 14 In below this insert 14 , the remainder of the bore 12 has the same diameter as the part between the surface 13 and the insert 14 . Accordingly the uppermost part of the bore 12 down to and including the surface 13 is a laterally (radially) enlarged portion of the bore 12 .
- the insert could be of metal or of cermet material.
- a metallic carrier rod 15 Extending into this upper part of the bore 12 is, as shown in FIG. 1 , a metallic carrier rod 15 , which at its upper end outside of the bore 12 is fixed in any convenient manner to a lifting device for raising and lowering the stopper rod, in use, in a vessel such as a tundish, in the normal manner.
- the carrier rod 15 is of circular cross-section, but is provided with a laterally (radially) enlarged portion in the form of an annular collar 16 , the external shape of which substantially matches the lower end of the bore 12 above the surface 13 together with the surface 13 itself.
- the upper part of the collar is cylindrical, as at 17 , whilst the lower part is in the form of a frustoconical surface 18 matching the frustoconical seating surface 13 .
- the carrier rod 15 is of its normal circular diameter, but this is provided with an external thread at the position of the insert 14 , so that the engagement of the rod 15 with the insert 14 enables a lifting of the carrier rod 15 to be transmitted to the stopper rod body 11 so as to lift or lower the stopper rod 10 in use in the normal manner.
- a graphoil seal 19 there is disposed between the corresponding frustoconical surfaces 13 and 19 a graphoil seal 19 .
- a problem with the prior art system shown in FIG. 1 is that when the stopper rod becomes heated, in use, the thermal expansion of the carrier rod 15 leads to reduced pressure being applied to the graphoil seal 19 , resulting in leakage.
- FIG. 2 The embodiment of the present invention shown in FIG. 2 is designed to solve that problem.
- all the features of the stopper rod shown in FIG. 1 are present in FIG. 2 and have accordingly been numbered identically, but with the suffix a.
- an insert in the form of a nut 20 is threadedly engaged on the carrier rod 15 a at a position somewhat above the upwardly facing surface of the cylindrical part 17 of the collar 16 so that, as shown, the upper face of the nut 20 is substantially flush with the upper face of the stopper rod body 11 .
- sealing means in the form, for example, of a packing gland seal 21 .
- this seal 21 would be compressed by the screwing down of the nut 20 , even when the stopper rod is not heated, so that there some radial sealing as shown by the arrows at the seal 21 in FIG. 2 . Accordingly instead of the bore 12 being open at above the collar 16 as in FIG. 1 , this part of the bore 12 now receives the nut 20 and seal 21 as shown.
- stopper rods some means of restraint at the top of the stopper rod body could be provided around the part of the carrier rod which extends out of this end of the stopper rod body. Such means will be described in relation to FIG. 3 , and it will be understood that these could be applied equally to the arrangement of FIG. 2 .
- the embodiment of the invention shown in FIG. 3 is similar in many respects to that shown in FIG. 2 and again like components will be similarly numbered, but with the prefix b. Accordingly it can be seen that the stopper rod shown in FIG. 3 comprises a refractory/ceramic stopper rod body 11 b with a longitudinal bore 12 b extending therethrough from its open upper end.
- This upper laterally (radially) enlarged part of the bore 12 b is formed with a seating surface 13 b of frustoconical form, and spaced below this surface 13 b there is pressed into the material of the body 11 a fixing insert 14 b with which an externally threaded end of the metallic carrier rod 15 b is engaged so that a lifting or lowering of the carrier rod will result in a corresponding lifting or lowering of the stopper rod in its vessel.
- the carrier rod 15 b which is preferably metallic, has a central gas passage 22 extending therethrough. It is provided externally with a collar 16 b made up of an upper cylindrical part 17 b and a lower part which has a frustoconical undersurface 18 b . As with the FIG. 2 arrangement, a seal 19 b , preferably a graphoil seal, is trapped between the frustoconical surface 18 b and the seating surface 13 b to provide a gas tight seal when the stopper rod is unheated.
- a seal 19 b preferably a graphoil seal
- a screw thread 23 is provided, for example by pressing, into the inner surface of the upper part of the bore 12 b and an insert in the form of an annular collar 24 or equivalent is screw-threadedly engaged with the thread 23 , there being, as shown, radial clearance between the inner cylindrical surface of the collar and the outer cylindrical surface of the carrier rod 15 b .
- This is in contrast to the FIG. 2 arrangement, where this radial clearance can be provided between the external surface of the nut 20 and the inner cylindrical surface of the bore in which the nut is received.
- the collar 24 is screwed down onto the seal 25 which is compressed thereby. Accordingly when the stopper rod is unheated, there is sealing both by way of the seal 19 b and also by way of the seal 25 , both of which seals are under compression. However as the stopper rod is heated, and the carrier rod 15 b expands, the seal 19 b is likely to start to leak in the normal manner as the compression thereof decreases due to the expansion of the carrier rod 15 b . However the upper seal 19 b , which is restrained by the fixed screwed-in collar 24 , will be subject to additional compressive forces between the expanding carrier rod 15 b and the retained collar 24 to provide an effective gas-tight seal. FIG.
- FIG 3 shows a conventional washer 26 on the carrier rod 15 b at the top of the stopper rod body 11 b , this washer being field down onto the top of the stopper rod body by a nut 27 which is screw threaded onto the carrier rod 15 b , the washer and nut providing a conventional lock at the top of the stopper rod body.
- FIG. 4 embodiment where the thread 23 a for the engagement of the collar 24 is provided by a ceramic insert 28 co-pressed into the stopper rod body to form part thereof. As shown, the upper part of the seal 25 is received in a lower non-threaded part of the insert 28 .
- the stopper rod of the invention shown in FIG. 5 is similar in several respects to that shown in FIG. 3 , having a stopper rod body 11 c of refractory/ceramic material with a central, longitudinally extending circular cross-section bore 12 c , which is open at the end of the stopper rod which is uppermost in use.
- This upper laterally (radially) enlarged part of the bore 12 c is formed with a seating surface 13 c of frustoconical form, and spaced below this surface there is pressed into the material of the body 11 c a (ceramic) fixing insert 14 c with which an externally threaded end of the preferably metallic carrier element in the form of a rod 15 c is engaged, so that a lifting or lowering of the carrier rod will result in a corresponding lifting or lowering of the stopper rod in its vessel.
- the carrier rod 15 c has a central gas passageway through it. It has an external collar 16 c made up of an upper cylindrical part 17 c and a lower part with a frustoconical undersurface 18 c .
- a seal 19 c preferably a graphoil seal, is trapped between the surface 18 c and the seating surface 13 c to provide a gas tight seal when the stopper rod is unheated.
- a conventional washer 26 c is received on the carrier element, as with the FIG. 3 embodiment, with a conventional insert in the form of a nut 27 c , also as in the FIG. 3 embodiment, being engaged on the screw thread 28 , to force the washer downwardly when the nut is tightened.
- the washer is of a diameter much greater than that of the bore 12 c at the top of the stopper rod body.
- the nut 21 c is now tightened, as shown at the right hand side of the drawing, it moves down the screw-thread 28 of the carrier rod and forces the washer 26 c axially downwardly axially to compress the seals 25 a , 25 b to the position shown at the right hand side, with the washer engaging the top of the stopper rod body.
- the axial compression of the seals causes them to expand radially and form a gas-tight seal (as shown) between the carrier rod and the stopper rod body.
- the washer could be sized to be received in the upper end of bore 12 c and thus at least partly received therein when it axially compresses the seals 25 a , 25 b .
- the insert screw-threaded on the carrier rod such as nut 27 c , could also at least partly be received in the bore 12 c pressing down on the washer.
- the further sealing means could, in any embodiment, be a single seal or any suitable number of seals.
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Casting Support Devices, Ladles, And Melt Control Thereby (AREA)
- Continuous Casting (AREA)
- Lift Valve (AREA)
- Coating Apparatus (AREA)
- Treatment Of Steel In Its Molten State (AREA)
Abstract
A stopper rod for controlling the flow of molten steel from a tundish has a metal carrier element partly received in an internal passageway of the stopper rod, the carrier element compressing sealing means between a frustoconical undersurface of a laterally enlarged portion thereof and a complementary seating surface of the stopper rod passageway, there being an insert threadedly engaged with one of the carrier element and stopper rod body at a position above a laterally enlarged portion of the carrier element, with further sealing means disposed between said insert and the carrier element. Preferably the insert is a nut screwed down onto a washer which compresses the further sealing means.
Description
- This invention relates to a stopper rod for controlling the flow of molten metal, for example from a vessel, such as a tundish, to a mould, and more preferably, to a stopper rod for supplying an inert gas to the melt in the vessel.
- Such a stopper rod is well known, it being moved in the direction of its longitudinal axis by a lifting device external to the vessel in which the stopper rod is disposed, so that an outlet opening in the base of the vessel, into which the stopper rod fits at its lowest position, shutting it off completely, is opened either more or less. The flow of metal through the opening is thus controllable.
- However extreme conditions prevailing in the processing of steel place severe demands on the materials and the engineering of the stopper rod, which has to withstand the effects of molten metal over the course of many hours. It must also be able to withstand the wide variations in temperature acting on the stopper rod during a pouring process. Moreover where the stopper rod serves to introduce an inert gas to the metal melt, it is important that no air reaches the interior of the stopper rod and thus the metal melt through the connection between the stopper rod body and the part of the lifting device which extends into said body, since this would lead to increased oxidation and thus a deterioration in steel quality. This connection is particularly problematical owing to the high thermal and mechanical loads acting on the connection. The difference in respective thermal expansion coefficients between different materials involved in the connection, in particular, needs to be compensated or allowed for.
- An object of the invention is to provide a stopper rod in an improved form.
- According to the invention there is provided a stopper rod comprising a refractory material stopper rod body having an internal passageway extending from a first end of the body towards a second end thereof, a metal carrier element having one of its ends received in said passageway, the carrier element having a laterally enlarged portion received in a laterally enlarged portion of the passageway, which passageway portion defines a seating surface, and sealing means between said seating surface and an underside of the laterally enlarged portion of the carrier element, wherein an insert is threadedly engaged with one of the carrier element and the stopper rod body at a position above said laterally enlarged portion of the carrier element, with further sealing means being disposed between said insert and the carrier element.
- Preferably the carrier element, which serves, in use, to connect the stopper rod to a lifting device, has a gas supply passage extending therethrough.
- Desirably the sealing means is a graphoil seal. In one embodiment the insert is threadedly engaged with the carrier element. In that embodiment the further sealing means is a packing gland seal. In another embodiment the insert is threadedly engaged with the stopper rod body. In that embodiment the further sealing means is a graphoil seal, which is preferably thicker than the graphoil seal forming said sealing means. In a still further embodiment the insert is threadedly engaged with a ceramic insert which is preferably pressed into the stopper rod to form part thereof.
- Conveniently the sealing means is disposed between complementary frustoconical surfaces respectively of the enlarged portion of the carrier element and said seating surface. Until the stopper rod heats up, the sealing means is compressed between the carrier element and the stopper rod body and provides a gas-tight seal therebetween. As the stopper rod heats up, gas tightness is maintained by the further sealing means, even if the seal provided by the sealing means starts to leak due to the expansion of the metal carrier element.
- Advantageously in said one embodiment the insert is engaged with a complementary thread on the carrier element. The insert is screwed down tightly on the further sealing means to effect radial sealing to the inner annular wall of the passageway of the stopper rod body. On expansion of the metal carrier element, the whole assembly simply slides up fractionally, but the force on the further sealing means, and hence the gas-tightness, is maintained.
- In said another embodiment the insert is a collar, which can be metallic or ceramic, threadedly engaged with a corresponding thread at an upper inner surface of the internal passageway in the stopper rod body. The thread can be pressed in the stopper rod body passageway, or provided by a pressed-in ceramic insert forming part of the stopper rod body. Initially the collar is tightened to compress the further sealing means. On expansion of the metal carrier element, the further sealing means will be subject to additional compressive forces between the expanding carrier element and the restrained collar to provide an effective gas-tight seal.
- In a preferred embodiment according to the present invention the insert is in the form of a nut screw-threadedly engaged on the carrier element, which nut, when tightened, effects axial compression of said further sealing means, resulting in sealing between the stopper rod body and the carrier element.
- The nut preferably effects axial compression of said further sealing means through the intermediary of a washer. Desirably the washer is located around the carrier element at one end of the stopper rod body. Conveniently the washer is larger than the further sealing means, and particularly of larger diameter than the diameter of the upper end of the internal passageway in the stopper rod body, in which upper end the further sealing means is received. The further sealing means is preferably two graphoil seals which stand proud of said upper end of the stopper rod body when the nut is untightened, and are axially compressed into said upper end of the passageway when the nut is tightened onto the washer to cause the washer axially to compress the graphoil seals.
- The invention will now be described, by way of an example, with reference to the accompanying drawings, in which:
-
FIG. 1 is a schematic side view of the interior of the upper end of a prior art stopper rod, -
FIG. 2 is a view likeFIG. 1 , for a stopper rod of the invention, and -
FIG. 3 is a similar view toFIG. 2 , for a stopper rod according to a further embodiment of the invention, -
FIG. 4 is a view likeFIG. 3 of a stopper rod according to a still further embodiment of the invention, and -
FIG. 5 is a split schematic cross-sectional view of the upper end of a stopper rod of the invention, the left half showing sealing means uncompressed, and the right half showing the sealing means compressed. -
FIG. 1 schematically shows the upper end of a priorart stopper rod 10 having a conventionalstopper rod body 11 of refractory/ceramic material. Extending centrally, axially within thestopper rod body 11 from the upper end thereof is a circular cross-sectionlongitudinal bore 12. A short way down from the upper open end of the bore, it is stepped inwardly to form a frustoconical shoulder defining aseating surface 13. Extending downwards from thissurface 13 is a constant diameter circular cross-section part, which leads to a radially enlarged portion of the bore in which is secured aceramic insert 14, the insert being secured to thestopper rod body 11. Below thisinsert 14, the remainder of thebore 12 has the same diameter as the part between thesurface 13 and theinsert 14. Accordingly the uppermost part of thebore 12 down to and including thesurface 13 is a laterally (radially) enlarged portion of thebore 12. Instead of being ceramic, the insert could be of metal or of cermet material. - Extending into this upper part of the
bore 12 is, as shown inFIG. 1 , ametallic carrier rod 15, which at its upper end outside of thebore 12 is fixed in any convenient manner to a lifting device for raising and lowering the stopper rod, in use, in a vessel such as a tundish, in the normal manner. Thecarrier rod 15 is of circular cross-section, but is provided with a laterally (radially) enlarged portion in the form of anannular collar 16, the external shape of which substantially matches the lower end of thebore 12 above thesurface 13 together with thesurface 13 itself. In other words the upper part of the collar is cylindrical, as at 17, whilst the lower part is in the form of afrustoconical surface 18 matching thefrustoconical seating surface 13. Below thecollar 16, thecarrier rod 15 is of its normal circular diameter, but this is provided with an external thread at the position of theinsert 14, so that the engagement of therod 15 with theinsert 14 enables a lifting of thecarrier rod 15 to be transmitted to thestopper rod body 11 so as to lift or lower thestopper rod 10 in use in the normal manner. As shown inFIG. 1 , there is disposed between the correspondingfrustoconical surfaces 13 and 19 agraphoil seal 19. Although not shown, it would normally be the case that there is a gas flow passageway through the centre of thecarrier rod 15 for transmitting inert gas, in the normal way, into the lower part of thebore 12 in thestopper rod body 11, this inert gas generally being supplied through an opening in the lower nose part of the stopper rod into the molten metal in the vessel in which the stopper rod is received. - A problem with the prior art system shown in
FIG. 1 is that when the stopper rod becomes heated, in use, the thermal expansion of thecarrier rod 15 leads to reduced pressure being applied to thegraphoil seal 19, resulting in leakage. - The embodiment of the present invention shown in
FIG. 2 is designed to solve that problem. As can be seen from the drawing, all the features of the stopper rod shown inFIG. 1 are present inFIG. 2 and have accordingly been numbered identically, but with the suffix a. To overcome the sealing problem identified with theFIG. 1 arrangement, it can be seen that inFIG. 2 an insert in the form of anut 20 is threadedly engaged on thecarrier rod 15 a at a position somewhat above the upwardly facing surface of thecylindrical part 17 of thecollar 16 so that, as shown, the upper face of thenut 20 is substantially flush with the upper face of thestopper rod body 11. Between the lower end of thenut 20 and the upper surface of thecylindrical part 17 of thecollar 16 is sealing means in the form, for example, of apacking gland seal 21. Generally thisseal 21 would be compressed by the screwing down of thenut 20, even when the stopper rod is not heated, so that there some radial sealing as shown by the arrows at theseal 21 inFIG. 2 . Accordingly instead of thebore 12 being open at above thecollar 16 as inFIG. 1 , this part of thebore 12 now receives thenut 20 andseal 21 as shown. - Accordingly with the arrangement shown in
FIG. 2 radial sealing by means of theseal 21 is maintained even when there is thermal expansion of thecarrier rod 15 a (and nut 20), given that the nut is connected to thecarrier rod 15 a. Although, as the metalwork expands, the whole assembly simply slides up fractionally, the force on theseal 21, and hence the gas-tightness, is maintained, even though there may be leakage at the graphoil seal 19 a. Instead of being metallic, thenut 20 could be ceramic, of cermet or potentially of any other heat resisting, shape maintaining material, and both the seal 19 a and theseal 21 could be of materials different from those described. Although not shown with eitherFIG. 1 orFIG. 2 , it will be understood that, as is well known with stopper rods, some means of restraint at the top of the stopper rod body could be provided around the part of the carrier rod which extends out of this end of the stopper rod body. Such means will be described in relation toFIG. 3 , and it will be understood that these could be applied equally to the arrangement ofFIG. 2 . - The embodiment of the invention shown in
FIG. 3 is similar in many respects to that shown inFIG. 2 and again like components will be similarly numbered, but with the prefix b. Accordingly it can be seen that the stopper rod shown inFIG. 3 comprises a refractory/ceramicstopper rod body 11 b with alongitudinal bore 12 b extending therethrough from its open upper end. This upper laterally (radially) enlarged part of thebore 12 b is formed with aseating surface 13 b of frustoconical form, and spaced below thissurface 13 b there is pressed into the material of thebody 11 a fixinginsert 14 b with which an externally threaded end of themetallic carrier rod 15 b is engaged so that a lifting or lowering of the carrier rod will result in a corresponding lifting or lowering of the stopper rod in its vessel. - The
carrier rod 15 b, which is preferably metallic, has acentral gas passage 22 extending therethrough. It is provided externally with acollar 16 b made up of an uppercylindrical part 17 b and a lower part which has afrustoconical undersurface 18 b. As with theFIG. 2 arrangement, aseal 19 b, preferably a graphoil seal, is trapped between thefrustoconical surface 18 b and theseating surface 13 b to provide a gas tight seal when the stopper rod is unheated. - A
screw thread 23 is provided, for example by pressing, into the inner surface of the upper part of thebore 12 b and an insert in the form of anannular collar 24 or equivalent is screw-threadedly engaged with thethread 23, there being, as shown, radial clearance between the inner cylindrical surface of the collar and the outer cylindrical surface of thecarrier rod 15 b. This is in contrast to theFIG. 2 arrangement, where this radial clearance can be provided between the external surface of thenut 20 and the inner cylindrical surface of the bore in which the nut is received. - It can be seen from
FIG. 3 that trapped between the lower surface of thecollar 24 and the upwardly facing top surface of thecollar 16 b is athick graphoil seal 25, which radially seals against the inner surface of thebore 12 b below the upper internally threaded part thereof. - The
collar 24 is screwed down onto theseal 25 which is compressed thereby. Accordingly when the stopper rod is unheated, there is sealing both by way of theseal 19 b and also by way of theseal 25, both of which seals are under compression. However as the stopper rod is heated, and thecarrier rod 15 b expands, theseal 19 b is likely to start to leak in the normal manner as the compression thereof decreases due to the expansion of thecarrier rod 15 b. However theupper seal 19 b, which is restrained by the fixed screwed-incollar 24, will be subject to additional compressive forces between the expandingcarrier rod 15 b and the retainedcollar 24 to provide an effective gas-tight seal.FIG. 3 shows aconventional washer 26 on thecarrier rod 15 b at the top of thestopper rod body 11 b, this washer being field down onto the top of the stopper rod body by anut 27 which is screw threaded onto thecarrier rod 15 b, the washer and nut providing a conventional lock at the top of the stopper rod body. - It is believed that the arrangement shown in
FIG. 3 is advantageous in that the force on theseal 25 will increase as the metalwork expands. In some instances it may be necessary for the stopper to be banded externally to overcome any problems as a result of the need to thread the refractory material of the stopper rod body. - Any such problems with threading the refractory material of the stopper rod body are overcome by the
FIG. 4 embodiment, where the thread 23 a for the engagement of thecollar 24 is provided by aceramic insert 28 co-pressed into the stopper rod body to form part thereof. As shown, the upper part of theseal 25 is received in a lower non-threaded part of theinsert 28. - Accordingly with each of the embodiments shown in
FIGS. 2 , 3 and 4 the thermal expansion/sealing problem identified with the prior art stopper rods is overcome in a simple, yet effective manner. - The stopper rod of the invention shown in
FIG. 5 is similar in several respects to that shown inFIG. 3 , having astopper rod body 11 c of refractory/ceramic material with a central, longitudinally extending circular cross-section bore 12 c, which is open at the end of the stopper rod which is uppermost in use. This upper laterally (radially) enlarged part of thebore 12 c is formed with aseating surface 13 c of frustoconical form, and spaced below this surface there is pressed into the material of thebody 11 c a (ceramic) fixinginsert 14 c with which an externally threaded end of the preferably metallic carrier element in the form of arod 15 c is engaged, so that a lifting or lowering of the carrier rod will result in a corresponding lifting or lowering of the stopper rod in its vessel. - The
carrier rod 15 c has a central gas passageway through it. It has anexternal collar 16 c made up of an uppercylindrical part 17 c and a lower part with afrustoconical undersurface 18 c. Aseal 19 c, preferably a graphoil seal, is trapped between thesurface 18 c and theseating surface 13 c to provide a gas tight seal when the stopper rod is unheated. - Above the
collar 16 c, at least part of the carrier element outside of thebore 12 c is externally screw-threaded as shown at 28. Aconventional washer 26 c is received on the carrier element, as with theFIG. 3 embodiment, with a conventional insert in the form of anut 27 c, also as in theFIG. 3 embodiment, being engaged on thescrew thread 28, to force the washer downwardly when the nut is tightened. The washer is of a diameter much greater than that of thebore 12 c at the top of the stopper rod body. - Disposed around the
carrier rod 15 c and supported by the upwardly facing top annular surface of thecollar 16 c is further sealing means in the form of twographoil seals nut 27 c is in a loosened state, such that there is no force exerted by the nut on thewasher 26 c. The weight of the washer along acts on the seals, but does not axially compress them. Thus as they are not radially compressed there is no effective seal produced by them between the carrier rod and the stopper rod body. - However if the nut 21 c is now tightened, as shown at the right hand side of the drawing, it moves down the screw-
thread 28 of the carrier rod and forces thewasher 26 c axially downwardly axially to compress theseals - It will be understood that in an alternative embodiment, the washer could be sized to be received in the upper end of
bore 12 c and thus at least partly received therein when it axially compresses theseals nut 27 c, could also at least partly be received in thebore 12 c pressing down on the washer. In other words the arrangement could be similar to that ofFIG. 2 , but with the addition of the washer between the insert and the further sealing means. The further sealing means could, in any embodiment, be a single seal or any suitable number of seals. With these alternative embodiments it is not of course necessary for the seal or one or more of the seals to stand proud when uncompressed.
Claims (26)
1-25. (canceled)
26. A stopper rod comprising a refractory material stopper rod body having an internal passageway extending from a first end of the body towards a second end thereof, a metal carrier element having one of its ends received in said passageway, the carrier element having a laterally enlarged portion received in a laterally enlarged portion of the passageway, which passageway portion defines a seating surface, and sealing means between said seating surface and an underside of the laterally enlarged portion of the carrier element, wherein an insert is threadedly engaged with one of the carrier element and the stopper rod body at a position above said laterally enlarged portion of the carrier element, with further sealing means being disposed between said insert and the carrier element.
27. A stopper rod as claimed in claim 26 , wherein the insert is in the form of a nut screw-threadedly engaged on the carrier element, which nut, when tightened, effects axial compression of said further sealing means, resulting in sealing between the stopper rod body and the carrier element.
28. A stopper rod as claimed in claim 27 , wherein the nut effects axial compression of said further sealing means through the intermediary of a washer.
29. A stopper rod as claimed in claim 28 , wherein the washer is located around the carrier element at one end of the stopper rod body.
30. A stopper rod as claimed in claim 28 , wherein the washer is larger than the further sealing means.
31. A stopper rod as claimed in claim 30 , wherein the washer is of larger diameter than the diameter of the upper end of the internal passageway in the stopper rod body, in which upper end the further sealing means is received.
32. A stopper rod as claimed in claim 28 , wherein the further sealing means is two graphoil seals which stand proud of said upper end of the stopper rod body when the nut is untightened, and are axially compressed into said upper end of the passageway when the nut is tightened onto the washer to cause the washer axially to compress the graphoil seals.
33. A stopper rod as claimed in claim 26 , wherein the further sealing means comprise three separate graphoil seals.
34. A stopper rod as claimed in claim 26 , wherein the carrier element, which serves, in use, to connect the stopper rod to a lifting device, has a gas supply extending therethrough.
35. A stopper rod as claimed in claim 26 , wherein the sealing means is a graphoil seal.
36. A stopper rod as claimed in claim 26 , wherein the insert is threadedly engaged with the carrier element.
37. A stopper rod as claimed in claim 36 , wherein the further sealing means is a packing gland seal.
38. A stopper rod as claimed in claim 26 , wherein the insert is threadedly engaged with the stopper rod body.
39. A stopper rod as claimed in claim 38 , wherein the further sealing means is a graphoil seal.
40. A stopper rod as claimed in claim 39 , wherein the graphoil seal is thicker than the seal forming the sealing means.
41. A stopper rod as claimed in claim 26 , wherein the insert is threadedly engaged with a ceramic insert.
42. A stopper rod as claimed in claim 41 , wherein the ceramic insert is pressed into the stopper rod to form part thereof.
43. A stopper rod as claimed in claim 26 , wherein the sealing means is disposed between complementary frustoconical surfaces respectively of the enlarged portion of the carrier element and said seating surface.
44. A stopper rod as claimed in claim 43 , wherein until the stopper rod heats up, the sealing means is compressed between the carrier element and the stopper rod body and provides a gas-tight seal therebetween.
45. A stopper rod as claimed in claim 36 , wherein the insert is engaged with a complementary thread on the carrier element.
46. A stopper rod as claimed in claim 45 , wherein the insert is screwed down tightly on the further sealing means to effect radial sealing to the inner annular wall of the passageway of the stopper rod body.
47. A stopper rod as claimed in claim 38 , wherein the insert is a collar.
48. A stopper rod as claimed in claim 47 , wherein the collar is metallic or ceramic, threadedly engaged with a corresponding thread at an upper inner surface of the internal passageway in the stopper rod body.
49. A stopper rod as claimed in claim 48 , wherein the thread is pressed in the stopper rod body passageway.
50. A stopper rod as claimed in claim 49 , wherein the thread is provided by a pressed-in insert forming part of the stopper rod body.
Applications Claiming Priority (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB0511202.4 | 2005-06-02 | ||
GB0511202A GB0511202D0 (en) | 2005-06-02 | 2005-06-02 | Stopper rod |
GB0523894.4 | 2005-11-24 | ||
GB0523894A GB0523894D0 (en) | 2005-11-24 | 2005-11-24 | Stopper rod |
PCT/GB2006/001991 WO2006129091A2 (en) | 2005-06-02 | 2006-06-01 | Stopper rod |
Publications (1)
Publication Number | Publication Date |
---|---|
US20090152778A1 true US20090152778A1 (en) | 2009-06-18 |
Family
ID=37027483
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/921,090 Abandoned US20090152778A1 (en) | 2005-06-02 | 2006-06-01 | Stopper Rod |
Country Status (15)
Country | Link |
---|---|
US (1) | US20090152778A1 (en) |
EP (1) | EP1885516B1 (en) |
JP (1) | JP2008542032A (en) |
KR (1) | KR20080016723A (en) |
AR (1) | AR055963A1 (en) |
AT (1) | ATE500012T1 (en) |
AU (1) | AU2006253947A1 (en) |
BR (1) | BRPI0610966A2 (en) |
CA (1) | CA2610580A1 (en) |
DE (1) | DE602006020436D1 (en) |
EA (1) | EA200702645A1 (en) |
MX (1) | MX2007015023A (en) |
TN (1) | TNSN07451A1 (en) |
TW (1) | TW200709873A (en) |
WO (1) | WO2006129091A2 (en) |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP5022054B2 (en) * | 2007-02-07 | 2012-09-12 | 黒崎播磨株式会社 | Stopper structure and manufacturing method thereof |
KR100925440B1 (en) | 2008-01-28 | 2009-11-06 | 엘지전자 주식회사 | Method for allocating physical hybrid ARQ indicator channel |
JP5107127B2 (en) * | 2008-04-23 | 2012-12-26 | 助川電気工業株式会社 | Electromagnetic pump for molten metal |
KR101482071B1 (en) * | 2014-09-03 | 2015-01-14 | 주식회사 영진이엠티 | Stopper rod |
KR101584135B1 (en) | 2015-07-09 | 2016-01-11 | 신일인텍 주식회사 | Stopper rod |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4946083A (en) | 1988-12-29 | 1990-08-07 | Vesuvius Crucible Company | One-piece stopper rod |
DE4040189C1 (en) | 1990-12-15 | 1992-01-02 | Didier-Werke Ag, 6200 Wiesbaden, De | Ceramic plug for outlet from metallurgical vessel - has supporting pipe with annular space to form sealing face, and nut is screwed onto it through which gas is delivered |
DE9109536U1 (en) | 1991-08-01 | 1991-09-26 | Kissner, Walter, 6000 Frankfurt, De | |
DE9109532U1 (en) * | 1991-08-01 | 1991-10-10 | Radex-Heraklith Industriebeteiligungs Ag, Wien, At |
-
2006
- 2006-06-01 JP JP2008514190A patent/JP2008542032A/en active Pending
- 2006-06-01 MX MX2007015023A patent/MX2007015023A/en unknown
- 2006-06-01 EA EA200702645A patent/EA200702645A1/en unknown
- 2006-06-01 WO PCT/GB2006/001991 patent/WO2006129091A2/en active Application Filing
- 2006-06-01 DE DE602006020436T patent/DE602006020436D1/en active Active
- 2006-06-01 CA CA002610580A patent/CA2610580A1/en not_active Abandoned
- 2006-06-01 US US11/921,090 patent/US20090152778A1/en not_active Abandoned
- 2006-06-01 TW TW095119400A patent/TW200709873A/en unknown
- 2006-06-01 BR BRPI0610966A patent/BRPI0610966A2/en not_active Application Discontinuation
- 2006-06-01 AT AT06744052T patent/ATE500012T1/en active
- 2006-06-01 KR KR1020087000086A patent/KR20080016723A/en not_active Application Discontinuation
- 2006-06-01 EP EP06744052A patent/EP1885516B1/en active Active
- 2006-06-01 AU AU2006253947A patent/AU2006253947A1/en not_active Abandoned
- 2006-06-02 AR ARP060102310A patent/AR055963A1/en unknown
-
2007
- 2007-11-30 TN TNP2007000451A patent/TNSN07451A1/en unknown
Also Published As
Publication number | Publication date |
---|---|
ATE500012T1 (en) | 2011-03-15 |
EP1885516A2 (en) | 2008-02-13 |
MX2007015023A (en) | 2008-02-07 |
AU2006253947A1 (en) | 2006-12-07 |
WO2006129091A3 (en) | 2007-01-18 |
EA200702645A1 (en) | 2008-04-28 |
EP1885516B1 (en) | 2011-03-02 |
TNSN07451A1 (en) | 2009-03-17 |
TW200709873A (en) | 2007-03-16 |
WO2006129091A2 (en) | 2006-12-07 |
AR055963A1 (en) | 2007-09-12 |
CA2610580A1 (en) | 2006-12-07 |
BRPI0610966A2 (en) | 2019-05-14 |
DE602006020436D1 (en) | 2011-04-14 |
KR20080016723A (en) | 2008-02-21 |
JP2008542032A (en) | 2008-11-27 |
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