Low and reverse pressure application hydrodynamic pressurizing seals

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 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 the dead end circumferential groove of each sealing ring segment extends arcuately in direction of shaft rotation when the sealing ring segments are positioned proximate the annular surface, and one additional groove extending across the shaft-side face of each sealing ring segment, the additional groove includes an axial bore groove, a first longitudinal bore groove, a second longitudinal bore groove, a first pressure chamber, and a second pressure chamber, the first longitudinal bore groove and the second longitudinal bore groove each having a first end and a second end, the axial bore groove extends perpendicularly to a longitudinal axis of the sealing ring segment, the axial bore groove separate and apart from the dead end circumferential groove, the first ends in direct fluid communication with the axial bore groove adjacent to one end of the dead end circumferential groove, the second end of the first longitudinal bore groove in direct fluid communication with the first pressure chamber, the first pressure chamber in direct fluid communication with the dead end circumferential groove adjacent another end of the dead end circumferential groove, the second end of the second longitudinal bore groove in direct fluid communication with the second pressure chamber, a bleed hole extending from the second pressure groove to a joint between adjoining sealing ring segments such that fluid flow is directed into the joint by way of the bleed hole 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 the additional groove and into the dead end circumferential groove such that a fluid is pressured as it flows along the first longitudinal bore groove, fluid flow into the additional groove directed into the dead end circumferential groove by way of the axial bore groove, the first longitudinal bore groove, and the first pressure chamber;
• 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;
• directing fluid flow generated by the rotating shaft along the additional groove and into a joint between adjoining sealing ring segments such that the fluid is pressured as it flows along the second longitudinal bore groove, fluid flow into the additional groove directed into the joint by way of the axial bore groove, the second longitudinal bore groove, the second pressure chamber, and the bleed hole;
• 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.