Patent ID: 8408554
Filing Date: 2013-04-02
Classification: F16J

Abstract:
1. A method of sealing a liquid region from a gas region across an annular surface of a rotating shaft utilizing a plurality of adjoining annularly sealing ring segments facing the rotating shaft, each sealing ring segment having a dead end circumferential groove formed within a shaft-side face of each sealing ring segment at a position closer to the liquid region than to the gas region such that, when the sealing ring segments are positioned proximate the annular surface, the dead end circumferential groove of each sealing ring segment extends arcuately in direction of shaft rotation, and at least two additional grooves each consisting of a hydrodynamic shallow pocket along the shaft-side face of each sealing ring segment wherein each additional groove is in fluid communication with the dead end circumferential groove, each hydrodynamic shallow pocket having a pocket, an inlet extending from the pocket away from the dead end circumferential groove, an outlet, and a dam extending between the pocket and the outlet with a bleed slot passing through the dam, the outlet extending toward the dead end circumferential groove wherein the hydrodynamic shallow pocket, by way of the bleed slot and the outlet, is in fluid communication with the dead end circumferential groove comprising the steps of: urging the sealing ring segments toward the rotating shaft such that the sealing ring segments form a seal with the rotating shaft when the rotating shaft is not rotating; rotating the rotating shaft; directing fluid flow generated by the rotating shaft along each additional groove and into the dead end circumferential groove such that a fluid is pressured as it flows along each additional groove and into the dead end circumferential groove; redirecting the fluid within the dead end circumferential groove toward the rotating shaft so as to provide a lift force on the sealing ring segments that lifts the sealing ring segments away from the rotating shaft; and creating an air seal around the rotating shaft as the pressurized air within the dead end circumferential groove is urged toward the rotating shaft, thereby, maintaining sealing between the rotating shaft and the sealing ring segments during rotation and non-rotation of the rotating shaft.