Abstract: An impeller for a centrifugal gas compressor includes a stationary seal member that includes a plurality of seal tips. The impeller is operable to produce a flow of fluid. The impeller includes a hub having a front face and a back face. A plurality of blades extends from the front face. Each of the blades has an inducer portion and an exducer portion and cooperates with an adjacent blade and the front face to at least partially define one of a plurality of impeller channels. A portion of the flow of fluid passes through one of the impeller channels such that the flow of fluid defines a first pressure adjacent the inducer portion and a second pressure that is higher than the first pressure adjacent the exducer portion. A seal portion extends from the back face and includes a plurality of stepped surfaces. Each of the seal tips is disposed adjacent one of the stepped surfaces to define a plurality of seal points.

Abstract: A multi-stage fluid compression system includes a first centrifugal compressor stage having a first inlet and a first outlet and a second centrifugal compressor stage having a second inlet and a second outlet. The second inlet receives a flow of compressed fluid from the first outlet. A first variable-speed motor is coupled to the first centrifugal compressor stage and is operable to drive the first centrifugal compressor stage at a first speed. A second variable speed motor is coupled to the second centrifugal compressor stage and is operable to drive the second centrifugal compressor stage at a second speed. The first speed and the second speed are each independently variable.

Abstract: A centrifugal compressor includes an impeller that defines an outside diameter and is rotatable about an axis to provide a flow of compressed fluid. A portion of the compressed fluid passes around the outside diameter to define a leakage flow. An extension extends from the impeller and includes a first seal portion that has an average diameter that is greater than or equal to about 50 percent of the outside diameter. A stationary seal ring includes a second seal portion that has a plurality of teeth. The second seal portion is disposed adjacent the first seal portion to define a seal that inhibits the passage of the leakage flow.

Abstract: A stationary seal ring is adapted to cooperate with a housing and an impeller to define a seal. The impeller is rotatable about an axis and includes a first seal portion and a plurality of blades that define an outside diameter. The stationary seal ring includes an alignment surface engageable with the housing, and a plurality of teeth. Each tooth is spaced axially from an adjacent tooth to define a cavity therebetween. Each tooth includes a tooth tip that cooperates with the first seal portion to define a seal point. A first tooth disposed nearest to the blades has a first tip diameter. Each subsequent tooth has a tip diameter that is smaller than the first tip diameter.