Circumferential Back-to-Back Seal Assembly with Bifurcated Flow

摘要

A circumferential seal assembly capable of separating a gas into two separate flow paths before communication onto a pair of seal rings is presented. The seal assembly includes an annular seal housing, a pair of annular seal rings, a rotatable runner, and a plurality of groove structures. The seal housing is interposed between a pair of low pressure compartments. The seal rings are separately disposed within the seal housing and separately disposed around the rotatable runner. The groove structures are disposed along an outer circumferential surface of the rotatable runner. The gas is communicable onto the groove structures. Each groove structure bifurcates the gas before communication onto the seal rings. Flow within each groove structure may be further separable before the gas is communicated onto the seal rings. The gas forms a thin-film layer between the rotatable runner and each seal ring.

主权项

1. A circumferential back-to-back seal assembly with bifurcated flow comprising:
(a) an annular seal housing disposed between a pair of low pressure compartments, one said low pressure compartment includes a gas, another said low pressure compartment includes a lubricant, said annular seal housing has at least one inlet; (b) a first annular seal ring; (c) a second annular seal ring, said first annular seal ring and said second annular seal ring separately disposed within said annular seal housing, a high pressure gas communicable between said first annular seal ring and said second annular seal ring via said at least one inlet; (d) a rotatable runner, said first annular seal ring and said second annular seal ring disposed around said rotatable runner; (e) a plurality of groove structures disposed along an outer circumferential surface of said rotatable runner, said high pressure gas communicable onto said groove structures, each said groove structure separates said high pressure gas so that a first portion of said high pressure gas is directed onto said first annular seal ring to form a first thin-film layer between said rotatable runner and said first annular seal ring and a second portion of said high pressure gas is directed onto said second annular seal ring to form a second thin-film layer between said rotatable runner and said second annular seal ring; (f) a center ring disposed within said annular seal housing between said first annular seal ring and said second annular seal ring, said center ring has a plurality of holes communicable with said at least one inlet, said high pressure gas traverses said holes before communication onto said groove structures; and (g) a plurality of springs disposed between said center ring and each of said first annular seal ring and said second annular seal ring, said springs bias said first annular seal ring and said second annular seal ring away from said center ring.