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 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 segments are positioned proximate the shaft surface, the circumferential dead end groove of each segment extends arcuately in the direction of shaft rotation, and at least one additional groove formed on the shaft-side face of each sealing ring segment wherein the additional groove(s) is in fluid communication with the dead end circumferential groove, a bleed slot or a bleed hole directly extending from the dead end circumferential groove to a joint between adjoining sealing ring segments, comprising;

• directing fluid flow generated by the rotating shaft along the additional groove(s) and into the dead end circumferential groove such that the fluid is pressured as it flows along the additional groove(s) and into the dead end circumferential groove;
• creating an air seal around the rotating shaft as the pressurized air within the dead end circumferential groove is urged toward the rotating shaft;
• and redirecting pressurized air from the dead end circumferential groove to the joint between adjoining sealing ring segments through the bleed slot or the bleed hole such that the force of the pressured air is also exerted on the joint between adjoining sealing ring segments, thereby created an air seal within the joint and between the adjoining sealing ring segments.

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 segments are positioned proximate the shaft surface, the circumferential dead end groove of each segment extends arcuately in the direction of shaft rotation, and at least one additional groove, selected from the group consisting of a hydrodynamic inclined groove, a hydrodynamic shallow pocket, and an axial bore groove, formed on the shaft-side face of each sealing ring segment wherein the additional groove(s) is in fluid communication with the dead end circumferential groove, a bleed slot or a bleed hole directly extending from the dead end circumferential groove to a joint between adjoining the sealing ring segments, comprising;

• urging the sealing ring segments toward the shaft such that the sealing ring segments from a seal with the shaft when the shaft is not rotating;
• rotating the shaft;
• directing fluid flow generated by the rotating shaft along the additional groove(s) and into the dead end circumferential groove such that the fluid is pressured as it flows along the additional groove(s) and into the dead end circumferential groove;
• redirecting the pressurized fluid within the dead end circumferential groove toward the rotating shaft so as to provide a lift force on the seal segments that lifts the seal segments away from the rotating shaft;
• 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 a seal between the shaft and the sealing ring segments during rotation and non-rotation of the shaft;
• and
• redirecting pressurized air from the dead end circumferential groove to the joint between adjoining sealing ring segments through the bleed slot or the bleed hole such that the force of the pressured air is also exerted on the joint between adjoining sealing ring segments, thereby created an air seal within the joint and between the adjoining sealing ring segments.