GB2211449A

GB2211449A - Outlet valve for melt-vessel

Info

Publication number: GB2211449A
Application number: GB8725127A
Authority: GB
Inventors: Stephen Lee Lee
Original assignee: Thor Ceramics Ltd
Current assignee: Thor Ceramics Ltd
Priority date: 1987-10-27
Filing date: 1987-10-27
Publication date: 1989-07-05
Also published as: GB8725127D0

Abstract

The valve comprises a fixed lower insert (9) having a convex upper face (10). The insert (9) is made e.g. of zirconia and is keyed into an insert (4) of a less expensive and less durable material, e.g. aluminium graphite. The inserts (4) and (9) have aligned off-centre bores (6) and (12). A rotary elongate vertical shaft (14) has keyed into its lower end, an insert (16) e.g. of zirconia having a concave lower face (18) which mates with the face (10). The insert (16) has a side opening (19) capable of aligning with the bores (6) and (12) in at least one rotational position of the shaft (14). By providing mating faces (10, 18) on the inserts (9, 16) of more durable material, corrosion and erosion at the interface between the relatively rotatable parts is diminished. <IMAGE>

Description

Rotary outlet valve for melt-containing vessels Description This invention relates to rotary outlet valves for vessels containing molten material, eg. metal or glass.

More particularly but not exclusively, the invention relates to rotary outlet valves for tundishes and ladles arranged for the pouring of metal, eg. steel, into continuous casting moulds or ingot moulds.

A rotary outlet valve is known for melt-containing vessels, which valve comprises a fixed lower inlet piece mounted in the base of the vessel having an outlet bore passing therethrough from the inside to the outside of the vessel, and a rotary elongate vertical shaft located above and pressed down upon the lower insert piece, the insert piece having a convex upper face into which the outlet bore opens at a port offset from the axis of rotation of the shaft and the shaft having a mating concave face at its lower end with a side opening capable of aligning with the port in at least one rotational position of the shaft.

The mating faces of the insert and the shaft are subject to a great deal more erosion and corrosion than the remaining parts and the object of the invention is to provide resistance to these rigours at these faces without substantially increasing the cost of the valve.

According to the invention there is provided a rotary outlet valve for melt-containing vessels which valve comprises a fixed lower insert mounted in the base of the vessel having an outlet bore passing therethrough from the inside to the outside of the vessel, and a rotary elongate vertical shaft located above and pressed down upon the lower insert, the insert having a convex upper face into which the outlet bore opens at a port offset from the axis of rotation of the shaft and the shaft having a mating concave face at its lower end with a side opening capable of aligning with the port in at least one rotational position of the shaft, at least one of the mating face being presented by a keyed piece of greater resistance to erosion and corrosion than the remaining parts of the valve.

An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawing, mainly in axial section, of a rotary outlet valve in a tundish.

In the drawing, a rotary outlet vavle is shown in the base of a tundish 1 having a refractory lining 2.

In an opening in the tundish 1 and the lining 2 there is disposed a conventionat refractory outlet nozzle 3 surmounted by a spigoted insert piece 4 of a refractory material such as alumina graphite. The nozzle 3 and the insert piece 4 are set in monolithic ramming 5.

The piece 4 has a short bore 6 leading to a hollow 7 therein which opens into the interior of the nozzle 3. The bore 6 opens into a recess 8 in the top of the piece 4 which recess is square in plan or of some other non-circular shape. The piece 4 is surmounted by a dome piece 9 having a convex upper face 10 and a spigot 11 fitting into the recess 8. A bore 12 extends through the piece 9 from the bore 6 to an offest port 13 in the face 10. The piece 9 is made of a refractory material such as the more expensive zirconia which is highly resistant to erosion and corrosion.

A rotary elongate vertical shaft 14 is located above and pressed downwards. The lower end of the shaft proper has a square or other non-circular recess 15. A piece 16 of zirconia or other erosion and corrosionresistant material has a spigot 17 fitting into the recess 15 and a lower face 18 which is concave and mates with-the face 10. A side opening 19 is provided in the piece 16 and is capable (as shown) of aligning with the port 13 in one rotational position of the shaft 14.

It will be evident that the pieces 9 and 16 may be easily replaced. It may be preferably, in some instances, for either the piece 9 to cooperate directly with the shaft 14 or the piece 16 to cooperate directly with the piece 4.

Claims

1. A rotary outlet valve for melt-containing vessels which valve comprises a fixed lower insert mounted in the base of the vessel having an outlet bore passing therethrough from the inside to the outside of the vessel, and a rotary elongate vertical shaft located above and pressed down upon the lower insert, the insert having a convex upper face into which the outlet bore opens at a port offset from the axis of rotation of the shaft and the shaft having a mating concave face at its lower end with a side opening capable of aligning with the port in at least one rotational position of the shaft, at least one of the mating faces being presented by a keyed piece of greater resistance to erosion and corrosion than the remaining parts of the valve.

2. A valve according to claim 1, wherein each mating face is presented by a keyed piece of greater resistance to erosion and corrosion than the remaining parts of the valve.

3. A rotary outlet valve for melt-containing vessels, substantially as herein before described with reference to the accompanying drawing.