Plant and method for liquefying a flow of gas, comprising a cooling circuit which is provided with an upstream end which is intended to be connected to a source of pressurised gas to be liquified and a downstream end which is intended to be connected to a user member, the plant comprising, between the upstream and downstream ends, a set of members which are intended to liquefy the gas and comprise at least one exchanger for cooling the gas, and at least one expansion turbine which is mounted on a rotary axle which is supported by at least one bearing of the gas-static type, the cooling circuit comprising a pressurised gas injection conduit having an upstream end which is intended to receive pressurised gas supplied by the source and a downstream end which is connected to the bearing in order to provide support to the rotary axle, the plant comprising a conduit for recovering the gas which has been used in the bearing, the conduit for recovering the gas comprising an upstream end which is connected to the bearing and a downstream end, characterised in that the downstream end of the conduit for recovering the as is connected to the cooling circuit between the upstream and downstream ends thereof in order to recycle at that location at least a portion of the gas which has been used to support the rotary axle of the bearing with a few to liquefying said gas.

The amount of consumption of gas is reduced when the gas is expanded to be cooled by using a plurality of expansion turbines. A high-pressure expansion turbine includes: a gas supply passage through which bearing gas is supplied to a bearing portion; and a gas discharge passage through which the bearing gas which has been supplied from the gas supply passage to the bearing portion is discharged from the bearing portion. A low-pressure expansion turbine includes: a gas supply passage through which the bearing gas is supplied to a bearing portion; and a gas discharge passage through which the bearing gas which has been supplied from the gas supply passage to the bearing portion is discharged from the bearing portion. The bearing gas discharged from the gas discharge passage of the high-pressure expansion turbine is supplied to the gas supply passage of the low-pressure expansion turbine.

The amount of consumption of gas is reduced when the gas is expanded to be cooled by using a plurality of expansion turbines. A high-pressure expansion turbine includes: a gas supply passage through which bearing gas is supplied to a bearing portion; and a gas discharge passage through which the bearing gas which has been supplied from the gas supply passage to the bearing portion is discharged from the bearing portion. A low-pressure expansion turbine includes: a gas supply passage through which the bearing gas is supplied to a bearing portion; and a gas discharge passage through which the bearing gas which has been supplied from the gas supply passage to the bearing portion is discharged from the bearing portion. The bearing gas discharged from the gas discharge passage of the high-pressure expansion turbine is supplied to the gas supply passage of the low-pressure expansion turbine.

A bearing system including a frequency independent damper assembly and a bearing pad assembly. The damper assembly includes a housing, a plunger, a moving central post and a support spring. The plunger is movable within a housing to define a first primary damper cavity and a second primary damper cavity. The moving central post has defined therein a fluid channel for a pressurized working fluid flow. The support spring includes a plurality of flexible elements coupled to the housing and disposed radially outward of the first and second primary damper cavities. The support spring defines first and second accumulator cavity. A flow-through channel couples the first accumulator cavity to the second accumulator cavity. In an embodiment, the flow-through channel may be disposed within the moving central post. The bearing pad assembly includes a bearing pad including a plurality of bearing pad orifices coupled to the fluid channel in the moving central post.

A bearing system including a frequency independent damper assembly and a bearing pad assembly. The damper assembly includes a housing, a plunger, a moving central post and a support spring. The plunger is movable within a housing to define a first primary damper cavity and a second primary damper cavity. The moving central post has defined therein a fluid channel for a pressurized working fluid flow. The support spring includes a plurality of flexible elements coupled to the housing and disposed radially outward of the first and second primary damper cavities. The support spring defines first and second accumulator cavity. A flow-through channel couples the first accumulator cavity to the second accumulator cavity. In an embodiment, the flow-through channel may be disposed within the moving central post. The bearing pad assembly includes a bearing pad including a plurality of bearing pad orifices coupled to the fluid channel in the moving central post.

An aspirating face seal between high and low pressure regions of a turbomachine at a juncture between rotatable and non-rotatable members of turbomachine includes gas bearing rotatable and non-rotatable face surfaces. Primary and starter seal teeth and optional deflector seal tooth are mounted on seal teeth carrier on rotatable member. Non-rotatable face surface is mounted on an annular slider on the non-rotatable member. A pull-off biasing means urges the annular slider away from the rotatable member and the non-rotatable face surface away from the rotatable surface. A secondary seal is in sealing engagement with the annular slider in the low pressure region and the pull-off biasing means is located radially outwardly of the annular slider in the high pressure region. Biasing means may include coil springs within spring chambers of circumferentially spaced cartridges. Tongues extend inwardly from spring chambers into grooves in slider.

A circumferential seal assembly suitable for forming a thin film between a rotatable runner and a sealing ring is presented. The assembly includes an annular seal housing, a rotatable runner, an annular seal ring, and a plurality of groove structures. Each groove structure includes a groove and an optional feed groove. The groove includes at least two adjoining steps defined by base walls arranged to decrease depthwise. Two adjoining base walls are disposed about a base shoulder. Each base shoulder locally redirects a longitudinal flow to form an outward radial flow in the direction of the annular seal ring. The base walls are bounded by and intersect a pair of side walls. A side wall includes side shoulders which narrows the groove widthwise and locally redirects the longitudinal flow to form a lateral flow in the direction of the other side wall. Outward and lateral flows separately or in combination enhance stiffness of a thin-film layer between the annular seal ring and the rotatable runner.

A circumferential seal assembly suitable for forming a thin film between a rotatable runner and a sealing ring is presented. The assembly includes an annular seal housing, a rotatable runner, an annular seal ring, and a plurality of groove structures. Each groove structure includes a groove and an optional feed groove. The groove includes at least two adjoining steps defined by base walls arranged to decrease depthwise. Two adjoining base walls are disposed about a base shoulder. Each base shoulder locally redirects a longitudinal flow to form an outward radial flow in the direction of the annular seal ring. The base walls are bounded by and intersect a pair of side walls. A side wall includes side shoulders which narrows the groove widthwise and locally redirects the longitudinal flow to form a lateral flow in the direction of the other side wall. Outward and lateral flows separately or in combination enhance stiffness of a thin-film layer between the annular seal ring and the rotatable runner.

A noncontacting intershaft seal system includes force generating mechanisms to reduce contact related effects. A sealing system includes an outer shaft that has a hollow interior. An inner shaft extends through the hollow interior of the outer shaft. Spaced apart end plates encircle and rotate with the inner shaft. A gland opening is defined between the inner and outer shafts and between the end plates. A ring is disposed in the gland opening. The end plates and/or the ring include force generating elements that generate force to separate the ring from the end plates, reducing contact related heat generation and wear.

A method of damping a vibration in a rotatable member and a damping system for a rotatable machine are provided. The damping system includes one or more damping stages. The rotatable machine further comprising a casing at least partially surrounding the rotor. The casing includes inwardly extending vanes that include a radially outer root, a radially inner distal end, and a stationary body extending therebetween. The one or more damping stages includes a damper supportively coupled between one or more roots of the plurality of vanes and the casing, an air bearing fixedly coupled to one or more distal ends of the plurality of vanes and configured to bear against the rotatable body wherein the damping stage is configured to receive vibratory forces from the rotatable body through the air bearing and the vane and ground the received forces to the casing through the damper.