US Patent 7255352 Pressure balanced brush seal

A brush seal extends between static and rotary components. The brush seal includes a fence on the high pressure side, a bristle pack behind the fence, a bristle pack backing plate and a pressure plate. The backing plate includes a plurality of circumferentially and radially spaced arcuate slots arrayed in staggered relation about the brush seal segment. The pressure plate includes radially extending grooves opening toward the backing plate and intersecting each of the slots along that radius to afford a substantially uniform distribution of pressure on the downstream side of the bristle backing plate. In another embodiment, the grooves extend along the downstream faces of the bristle backing plate.