US 4,946,083 A · One-piece stopper rod

Abstract

A one-piece refractory stopper rod has an axial bore formed therein for the introduction of inert gas into molten steel within a tundish. A metal bushing insert is compressed into the refractory stopper rod and has a threaded bore which is positioned coaxially with the bore of the stopper rod body. A metal attachment rod having an axial bore therethrough and a threaded lower shank portion is secured within the threaded bore of the metal bushing insert. The metal attachment rod has an upper threaded shank which is adapted to be secured to a stopper rod lifting mechanism associated with the tundish. The metal rod further includes a flanged portion intermediate the upper and lower shank portions which carries an annular chamfered surface. The annular chamfered surface faces a like annular chamfered surface formed in the bore of the stopper rod to define a gas-tight seal at a sealing interface therebetween. The upper shank includes an internally threaded portion adapted to receive a threaded fitting for the introduction of a pressurized inert gas to the stopper rod bore. The attachment between the metal rod and the refractory stopper rod provides increased strength, while minimizing gas leakage and air infiltration compared to prior stopper rod attachment configurations.

Claims16

Dependent claims

A stopper rod adapted for attachment to an inert gas supply line and lifting mechanism adjacent a metallurgical vessel, comprising:

an elongated stopper rod body of a refractory material having an upper end and a lower end and an axial bore extending from the upper end to the lower end and including means at the lower end communicating with the axial bore for emitting an inert gas to an exterior surface thereof, said axial bore having an enlarged diameter countersunk portion including an annular sealing surface spaced from the upper end of the stopper rod body adapted to form a gas tight seal with a like annular surface carried by a threaded metal rod attached to the inert gas supply line and lifting mechanism adjacent to the metallurgical vessel;
and
a metal bushing insert copressed and fired within the stopper rod body positioned beneath said annular sealing surface, said bushing insert including an outer sidewall carrying means for providing a mechanical interlock with the refractory material of the stopper rod, and having a threaded bore positioned coaxially with the bore of the stopper rod body and adapted to threadably receive the threaded metal rod for attachment to said inert gas supply line and lifting mechanism.

A stopper rod assembly for use in the continuous casting of steel from a metallurgical vessel comprising in combination:

an elongated stopper rod body of a refractory material, having an upper end and a lower end and an axial bore extending from the upper end to the lower end and including means at the lower end communicating with the axial bore for emitting an inert gas to an exterior surface thereof, said axial bore including an enlarged countersunk portion having an annular sealing surface spaced from the upper end of the stopper rod;
a metal bushing insert copressed and fired within the stopper rod body spaced a distance from the upper end thereof, said bushing insert having a threaded bore positioned coaxially with the bore of the stopper rod body, said bushing insert including an outer sidewall carrying means for interlocking with the refractory material of the stopper rod body during copressing and firing;
and
an elongated metal rod having an axial bore therethrough communicating with the bore of the stopper rod and a threaded lower shank portion which is secured within the threaded bore of the metal bushing insert, said metal rod also including an upper shank portion and a flanged portion carrying an annular sealing surface intermediate said upper and lower shank portions, said annular sealing surface facing said annular sealing surface of the stopper rod bore to define a gas sealing interface therebetween;
the upper shank portion adapted to receive a fitting for the supply of a pressurized inert gas to the respective axial bores of the metal rod and the stopper rod, said upper shank portion adapted to be secured to a lifting mechanism to permit the stopper rod to be vertically moved within the vessel.

2 more elements

Dependencies are inferred from the claim text.

One-piece stopper rod

Life of this patent

One-piece stopper rod

Life of this patent

Abstract

Claims16