Operation of a multistage compression system comprising at least one centrifugal compressor having a dry gas seal with opposed seal faces, for compressing a gas feed having a variable flow rate is improved by operating the or at least one centrifugal compressor in a low power mode where the opposed faces of the dry gas seal are not in contact during periods when gas flow through the centrifugal compressor(s) is not sufficient for normal operation. Such operation not only reduces damage to the dry gas seals and hence improves reliability, but also reduces the overall power requirement of the overall compression system.

Energy efficiency and/or operational stability of a multistage compression system comprising a plurality (N) of centrifugal compressors that is compressing a gas feed having a variable flow rate is improved by adjusting reversibly the load on each compressor in response to changes in the flow rate of the gas feed using a main recycle system to enable operation of the centrifugal compressors at turndown capacity during periods when the flow rate is below total turndown capacity for all of the compressors, and if necessary, using the local recycle systems in order to avoid activation of anti-surge control, and switching one or more centrifugal compressors into low power mode or shutdown mode as required.

A shaft sealing arrangement includes a first seal and a second seal, wherein the first seal is designed in the form of a lip seal and the second seal is designed in the form of a mechanical seal. When the shaft is at a standstill, the lip seal performs the sealing action and, when the shaft is rotating, the mechanical seal performs the sealing action.

A compressor wheel device comprises a compressor wheel attached to a rotary shaft and a thrust collar attached to the rotary shaft at a back surface of the compressor wheel. The compressor wheel includes: a wheel body part with a hub and at least one blade provided on an outer peripheral surface of the hub; and a sleeve part having a cylindrical shape projecting along an axis direction from a back surface of the hub and having an outer peripheral surface on which a sealing groove extending along a peripheral direction is formed. The thrust collar has a circular plate-like shape including: one surface including an abutting surface abutting on an end surface of the sleeve part and extending along a radial direction; and the other surface including a slidably-contacting surface slidably contacting a thrust bearing supporting the rotary shaft in a thrust direction and extending along the radial direction.

A bearing compartment seal for a gas turbine engine includes at least one seal ring defining an axis and having a radially inward facing sealing surface and a seal runner having a support constructed of a first material and an interface portion constructed of a second material. The interface portion includes a radially outward facing surface. A first coefficient of thermal expansion of the second material is at most approximately equal to a second coefficient of thermal expansion of the at least one seal ring.

A shaft sealing arrangement includes a first seal and a second seal, wherein the first seal is designed in the form of a lip seal and the second seal is designed in the form of a mechanical seal. When the shaft is at a standstill, the lip seal performs the sealing action and, when the shaft is rotating, the mechanical seal performs the sealing action.

The present invention relates to an electric compressor (9, 17) including a shaft (13) rotated by an electric motor by means of bearings (16), the shaft rotating a compressor wheel (14), the compressor (9) including two sealing segments (29a, 29b) mounted around the shaft (13) between the bearings (16) and the compressor wheel (14) and including a vent hole (31, 35, 38) for circulation of pollutant flows toward the outside of the compressor, the inlet of which is arranged between the two sealing segments, the vent hole including a non-return element (36).

A dry gas mechanical seal system configured to inhibit the emission of process gas. The mechanical seal system having tandem first and second stage seals, and a single separation gas supply subsystem configured to direct a supply of separation gas from an inlet through interfacing portions of the first stage seal into a process cavity and from the inlet through the interfacing portions of the second stage seal and out through an outlet to the atmosphere, thereby inhibiting the emission of process gas between a compressor housing and a rotating compressor shaft.

Provided is a seal device configured to prevent leakage of a fluid on an outer circumferential surface of a rotary shaft in a direction along an axis of the rotary shaft. The seal device includes an annular main body section disposed in a circumferential direction of the rotary shaft, and a plurality of at least two kinds of holes formed in an inner circumferential surface of the main body section opening and facing to the outer circumferential surface of the rotary shaft, and having different depths.

Disclosed is a device for regulating the compression force of a spring-spacer assembly provided in a mechanical shaft seal in a system including a motor and a pump or compressor. The device includes a spacer made from shape memory alloy, a spring in line with the spacer, and a heater proximate the spacer. When heated, the spacer contracts in length, resulting in a decrease in compression force. Also disclosed are systems and methods utilizing the device. The device is particularly useful when starting a pump or compressor to reduce friction in the mechanical seal. Existing mechanical seals can be easily retrofitted with the device.