A method for operating a pump, for conveying a fluid from a low-pressure side to a high-pressure side of the pump includes determining a current rate of change of pump vibrations and comparing the current rate of change with a limit for the rate of change or determining a current vibration of the pump and comparing the current vibration with a vibration amplitude limit for the vibration, storing the limit for the rate of change or the vibration amplitude limit in a surge controller, providing a control signal when the current rate of change reaches the limit or when the current vibration reaches the vibration amplitude limit, and changing a control variable of the pump by the control signal, such that the vibration is reduced and an unstable operating state of the pump is avoided.

A multiphase pump for conveying a multiphase process fluid includes a pump housing, a rotor and a radial bearing. The rotor is arranged in the pump housing and is configured to rotate about an axial direction. The radial bearing has a support carrier and a support structure to support the rotor with respect to a radial direction. The rotor includes a pump shaft and an impeller fixedly mounted on the pump shaft to convey the process fluid from a pump inlet to a pump outlet. A squeeze film damper is provided to reduce vibrations of the rotor, the squeeze film damper arranged around the support structure of the radial bearing, and having an radially outer surface. A damping gap is arranged between the support structure of the radial bearing and the radially outer surface of the squeeze film damper. The damping gap is configured to receive a damping fluid.

A method of determining a liquid volume fraction in a multi-phase gas is disclosed. The method includes: a) measuring a first compressor operating parameter; b) selecting a tentative liquid volume fraction of the gas processed by the compressor; c) based on stored data representing a compressor operative curve for the tentative liquid volume fraction, determining an estimated value of a second compressor operating parameter, as a function of the first compressor operating parameter; d) measuring an actual value of the second compressor operating parameter; e) comparing the actual value of the second compressor operating parameter to the estimated value of the second compressor operating parameter and determining an error therefrom; f) based on the error, selecting a different tentative liquid volume fraction and repeating (c) to (e) until an error value equal to or lower than an error threshold is obtained.

A centrifugal gas compressor with rotating hollow housing and an independently rotating, turbine compresses gas bubbles in capillary tubes and recovers energy from the liquid drain (sometimes a liquid recycler). The housing rotatably retains an internal spool having the turbine. Gas-liquid emulsion fed to the capillaries generates compressed gas-liquid emulsion at a radially distal annular region in an annular lake within the spool. Compressed gas leaves the lake and is ported away. A turbine blade edge in spilt over liquid drives the turbine, converting angular velocity/momentum into shaft torque as recovered energy. Blade captured liquid is recycled to capillary inputs.

A centrifugal gas compressor with rotating hollow housing and an independently rotating, turbine compresses gas bubbles in capillary tubes and recovers energy from the liquid drain (sometimes a liquid recycler). The housing rotatably retains an internal spool having the turbine. Gas-liquid emulsion fed to the capillaries generates compressed gas-liquid emulsion at a radially distal annular region in an annular lake within the spool. Compressed gas leaves the lake and is ported away. A turbine blade edge in spilt over liquid drives the turbine, converting angular velocity/momentum into shaft torque as recovered energy. Blade captured liquid is recycled to capillary inputs.

A cavitation boiler segment includes a rotor to be coupled with a rotating inner drum and a stator surrounding the rotor segment. The rotor and the stator each include drums with two banks of annular apertures, which overlap to define two cavitation regions. The rotor includes a web bifurcating the rotor between the apertures into an upstream side and a downstream side, each forming a separate fluid passage between a face of the rotor and a bank of apertures. The stator includes a casing enclosing the stator apertures in a fluid passageway. In operation, fluid flows into a first side of the rotor, across a first cavitation region and into the stator, then back across the second cavitation region and into the second side of the rotor where the fluid may flow into a first side of an adjacent segment.

A multistage pump for installation on a sea ground includes a common housing, a pump unit arranged in the common housing, a drive unit arranged in the common housing, and a coupling. The common housing includes a pump inlet and a pump outlet, the pump unit including a plurality of impellers to convey a compressible fluid from the pump inlet to the pump outlet, and a pump shaft, on which each impeller is mounted, each impellepr being a radial or semi-axial impeller. The drive unit includes a drive shaft to drive the pump shaft, and an electric motor configured to rotate the drive shaft about an axial direction. The coupling couples the drive shaft to the pump shaft. The pump unit conveys the fluid in a dense phase at the pump outlet, and at least two impellers of the plurality of impellers have a different specific speed.

A fluid vacuum pump includes a motor assembly including a single motor or multiple motors, where one motor may be configured for operation in a first medium and another motor may be configured for operation in a second medium; an impeller assembly including a single impeller, which may of a fixed or variable configuration, or multiple impellers, where one impeller may be configured for operation in a first medium and another impeller may be configured for operation in a second medium; and a linkage operatively connecting and adjustably transmitting power from the motor assembly to the impeller depending on the type of medium present.

A multiphase pump for pumping a multiphase mixture containing hydrocarbon includes a separation system and a supply system. The separation system has a first separation stage configured to at least partly separate at least one portion of the multiphase mixture into a plurality of phase-enriched components, the first separating stage including an impeller attached to a pump shaft of the multiphase pump and being having an inlet side formed by a seal. The supply system is configured to supply a liquid-enriched liquid component as a lubricant to a pump element to be lubricated.

A multiphase pump for pumping a multiphase mixture containing hydrocarbon includes a separation system and a supply system. The separation system has a first separation stage configured to at least partly separate at least one portion of the multiphase mixture into a plurality of phase-enriched components, the first separating stage including an impeller attached to a pump shaft of the multiphase pump and being having an inlet side formed by a seal. The supply system is configured to supply a liquid-enriched liquid component as a lubricant to a pump element to be lubricated.