Low and reverse pressure application hydrodynamic pressurizing seals

A seal assembly for sealing a liquid region from a gas region across an annular surface of a rotating shaft comprising:

• a plurality of adjoining annularly sealing ring segments facing the rotating shaft wherein each sealing ring segment includes a dead end circumferential groove within a shaft-side face of each sealing ring segment such that, when the sealing ring segments are joined about 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 extending across the shaft-side face of each sealing ring segment leading to the dead end circumferential groove wherein each additional groove is in fluid communication with the dead end circumferential groove and directs fluid into the dead end circumferential groove;
• each additional groove is comprised of a 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 so as to direct fluid flow generated from rotation of the rotating shaft into the dead end circumferential groove.

A seal assembly for sealing a liquid region from a gas region across an annular surface of a rotating shaft comprising:

• a plurality of adjoining annularly sealing ring segments facing the rotating shaft wherein each sealing ring segment includes a dead end circumferential groove within a shaft-side face of each sealing ring segment such that, when the sealing ring segments are joined about 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 extending across the shaft-side face of each sealing ring segment leading to the dead end circumferential groove wherein each additional groove is in fluid communication with the dead end circumferential groove and directs fluid into the dead end circumferential groove, each additional groove is comprised of a hydrodynamic pocket having a shallow pocket, an inlet extending from the shallow pocket away from the dead end circumferential groove, an outlet, and a dam extending between the shallow pocket and the outlet with a bleed slot passing through the dam, the outlet extending toward the dead end circumferential groove wherein the hydrodynamic pocket, by way of the bleed slot and the outlet, is in fluid communication with the dead end circumferential groove so as to direct fluid flow generated from the rotating shaft into the dead end circumferential groove.