Stopper Rod

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.

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.