Sleeve seal for electric furnace electrodes

Patent metadata

Field	Value
Publication number	US-10100930-B2
Application number	US-201515307478-A
Country	US
Kind code	B2
Filing date	Apr 27, 2015
Priority date	Apr 28, 2014
Publication date	Oct 16, 2018
Grant date	Oct 16, 2018

Abstract

A highly flexible sealing arrangement designed to seal high-temperature furnace ports, particularly the electrode port of an electric furnace. The seal comprises an annular support member fixed to a flexible sealing member and employs the use of a garter spring to uniformly apply the desired amount of seal compression. The arrangement and flexibility of the sealing member allows the seal to adapt itself to the wide range of operating and upset conditions that typically exist for a furnace electrode seal. Frictional wear on the seal may be greatly reduced as the design inherently allows for a much lower amount of seal compression to be applied, furthermore, the seal is able to move axially which can significantly reduce wear caused by electrode regulation.

First claim

What is claimed is:

1. A seal assembly for sealing a substantially annular opening between a cylindrical surface and a fixed surface for use at temperatures not typically suitable for elastic materials, comprising:
(a) a sealing member having a secured edge arranged to be secured to the fixed surface and a movable edge arranged to engage the cylindrical surface, the sealing member being flexible and allowing displacement of the moveable edge parallel to and perpendicular to a vertical axis of the cylindrical surface; and
(b) a spring member located inside the movable edge of the sealing member, the spring member arranged to be in tension tangent to the cylindrical surface and force the moveable edge of the sealing member away from the secured edge and into sealing engagement with the cylindrical surface.

2. The seal assembly according to claim 1 , wherein the sealing member comprises a material which is resistant to temperatures up to about 1500° C.

3. The seal assembly according to claim 1 , wherein the sealing member comprises substantially inelastic, heat-resistant fibers comprised of ceramic or a heat-resistant metal.

4. The seal assembly according to claim 1 , wherein the sealing member comprises at least one flexible folding sheet having a pair of opposed edges, wherein the opposed edges of the sheet are located proximate to the secured edge of the sealing member.

5. The electrode seal assembly according to claim 4 , wherein the sealing member further comprises an additional outer sheet comprising a layer of flexible metal fibers or metal mesh.

6. The seal assembly according to claim 4 , wherein the spring member is enclosed within the at least one flexible folded sheet.

7. The seal assembly according to claim 4 , wherein the sealing member comprises a plurality of said flexible folded sheets, arranged in a plurality of layers.

8. The seal assembly according to claim 7 , wherein the sealing member has a toroidal shape and comprises a toroidal collar made up of said flexible folded sheets, and enclosing the spring member.

9. The seal assembly according to claim 8 , wherein the toroidal collar has a pear-shaped radial cross-section, with the moveable edge of the sealing member having a rounded profile.

10. The seal assembly according to claim 8 , wherein the toroidal collar comprises a woven arrangement of fibers.

11. The seal assembly according to claim 10 , wherein the woven arrangement of fibers approximates a double-ruled surface.

12. The seal assembly according to claim 1 , wherein, with the secured edge of the sealing member secured to the fixed horizontal surface, the moveable edge is free to move axially along the vertical axis by a predetermined amount to significantly reduce relative movement between the cylindrical surface and the movable edge of the sealing member.

13. The seal assembly according to claim 1 , wherein the sealing member and the spring member are both substantially annular, and wherein the sealing member includes a lap joint at which a first end and a second end of the sealing member are joined;
wherein the lap joint has a thickness which is substantially the same as a thickness of the remainder of the sealing member.

14. The seal assembly according to claim 1 , wherein the sealing member and the spring member are both substantially annular, and wherein the secured edge of the sealing member is located radially outwardly of the moveable edge.

15. The seal assembly according to claim 14 , comprising an electrode seal assembly, wherein:
the cylindrical surface comprises an outer cylindrical surface of an electrode;
the fixed surface comprises an edge of a port in a furnace roof of an electric furnace, wherein a lower end of the electrode extends through the port into the furnace, and the electrode is movable through said port along the vertical axis;
the opening between the cylindrical surface and the fixed surface comprises an annular gap between an outer cylindrical surface of the electrode and the edge of the port in the furnace roof; and
the moveable edge of the seal assembly being displaceable axially and radially relative to said vertical axis, permitting continuous engagement with the outer cylindrical surface of the electrode.

16. The seal assembly according to claim 15 , wherein a minimum inner diameter of the annular sealing member, with the electrode removed from the seal assembly, is less than a diameter of the electrode.

17. The electrode seal assembly according to claim 15 , wherein the fixed surface comprises an annular seal housing on the furnace roof, and wherein the secured edge of the sealing member is secured to the seal housing.

18. The electrode seal assembly according to claim 17 , wherein the secured edge of the sealing member is secured beneath a retaining plate of the seal housing.

19. The electrode seal assembly according to claim 17 , wherein the seal housing has an open top.

20. The electrode seal assembly according to claim 17 , further comprising an annular brick housing shield provided between the annular seal housing and the furnace roof.

21. The electrode seal assembly according to claim 20 , wherein the brick housing shield comprises an annular ring of refractory brick surrounding the port and partly covering the annular gap between the electrode and the port.

22. The electrode seal assembly according to claim 20 , further comprising a copper cooler provided between the brick housing shield and the furnace roof.

23. A seal assembly for sealing a substantially annular opening between a cylindrical surface and a fixed surface for use at temperatures not typically suitable for elastic materials, comprising:
(a) a sealing member having a secured edge arranged to be secured to the fixed surface and a movable edge arranged to engage the cylindrical surface, the sealing member being flexible and allowing displacement of the movable edge parallel to and perpendicular to a vertical axis of the cylindrical surface; and
(b) a spring member located inside the movable edge of the sealing member, the spring member arranged to be in compression tangent to the cylindrical surface such that it applies a force only to the movable edge of the sealing member, forcing the movable edge away from the secured edge and into sealing engagement with the cylindrical surface;
wherein the secured edge of the sealing member is located radially inwardly of the movable edge, and wherein the spring member is under compression.

Assignees

• Hatch Ltd

Inventors

• Haley Stephen D

Classifications

• F16J15/065

  fire resistant · CPC title

• F16J15/104

  characterised by structure · CPC title

• H05B7/12

  Arrangements for cooling, sealing or protecting electrodes · CPC title

• F16J15/0812 Primary

  with a braided or knitted body · CPC title

• F27D2099/0081

  Joint · CPC title