Patent ID: 8066475

Claim:
A labyrinth seal for a turbine having a stationary housing through which extends a rotating element wherein the turbine includes media flow regions of differential pressure, the labyrinth seal comprising: a first seal assembly comprising a first plurality of adjacent seal components extending generally radially from one of 1) a portion of the stationary housing and 2) a portion of the rotating element, said first plurality of seal components including at least one first seal fin structure and a second seal fin structure, said first seal fin structure comprising at least one circumferentially extending fin, said second seal fin structure comprising a plurality of circumferentially adjacent seal fins, each inclined at an angle with respect to said at least one circumferentially extending fin and spaced therefrom to define a circumferentially extending dam gap therebetween, and a second seal assembly comprising a second plurality of adjacent seal components extending generally radially from one of 1) a portion of the stationary housing and 2) a portion of the rotating element, said second plurality of seal components including at least one first seal fin structure and a second seal fin structure, said first seal fin structure comprising at least one circumferentially extending fin, said second seal fin structure comprising a plurality of circumferentially adjacent seal fins, each inclined at an angle with respect to said at least one circumferentially extending fin and spaced therefrom to define a circumferentially extending dam gap therebetween, wherein a cooling media passage is defined between said first and second seal assemblies, said at least one circumferential seal fin of each said seal assembly being disposed between said second seal fin structure thereof and said cooling media passage.