Low leakage finger seal
A seal for an exhaust duct includes a metal mesh member sandwiched between an outer plate and an inner plate. The seal includes a plurality of flexible members defined by a plurality of slots in both the inner and outer plates. The flexible members provide for expansion and contraction along with creating flexibility in the region of contact between the seal land and the seal. The metal mesh member substantially eliminates gaps and leak paths created through the slots. The metal mesh member is composed of a plurality of interwoven wire strands impregnated with a high temperature elastomeric sealant. The impregnation of high temperature elastomeric sealant over the metal mesh member improves sealing while maintaining the desired flexibility of the seal.
1. A seal assembly comprising:
a first sheet including a first plurality of slots;
a second sheet including a second plurality of slots; and
a flexible metal member disposed between said first sheet and said second sheet, said flexible metal member including a plurality of intermeshing metal strands disposed within a high temperature elastomeric sealant, wherein said flexible member includes a welded joint to at least one of the first sheet and said second sheet.
2. The assembly as recited in claim 1 wherein said second plurality of slots are staggered relative to said first plurality of slots.
3. The assembly as recited in claim 1 , wherein said first plurality of slots define a corresponding first plurality of flexible portions, and said second plurality of slots define a corresponding second plurality of flexible portions.
4. The assembly as recited in claim 1 , wherein said flexible metal member is attached to one of said first sheet and said second sheet.
5. The assembly as recited in claim 1 , wherein said flexible metal member extends longitudinally through said slots within said first and said second plurality of slots.
6. The assembly as recited in claim 1 wherein said flexible metal member comprises a porosity between 20 and 5.
7. The assembly as recited in claim 1 wherein said flexible metal member comprises a porosity between 10 and 5.
8. The assembly as recited in claim 1 , wherein said welded joint comprises a plurality of welded joints spaced apart from each other and disposed longitudinally across the seal assembly.
9. An exhaust duct assembly comprising:
a fixed member;
a movable member;
a seal fixed to one of said fixed member and said movable member, said seal including an outer layer having a first plurality of slots, an inner layer having a second plurality of slots, and a metal mesh member impregnated with a high temperature elastomeric sealant disposed between said outer layer and said inner layer, wherein sad metal mesh member includes a welded joint to at least one of the inner layer and the outer layer.
10. The assembly as recited in claim 9 wherein said metal mesh member comprises a plurality of intermeshed metal strands.
11. The assembly as recited in claim 9 wherein said high temperature elastomeric sealant is capable of withstanding temperatures of an exhaust combustion gas.
12. The assembly as recited in claim 9 wherein said first plurality of slots define a corresponding first plurality of flexible portions of said outer layer, and said second plurality of slots define a corresponding second plurality of flexible portions of said inner layer.
13. The assembly as recited in claim 10 wherein said first plurality of slots are offset relative to said second plurality of slots in a radial direction.
14. The assembly as recited in claim 9 , wherein said welded joint comprises a plurality of welded joints spaced apart from each other and disposed longitudinally across the said seal.