A control system comprising: a suction line; an exhaust line; an operating liquid line; a liquid ring pump comprising a suction input coupled to the suction line, an exhaust output coupled to the exhaust line, and a liquid input coupled to the operating liquid line; a motor configured to drive the liquid ring pump; a first sensor configured to measure a first parameter of an exhaust fluid of the liquid ring pump; a second sensor configured to measure a second parameter of a gas being received by the liquid ring pump via the suction line; and a controller operatively coupled to the first sensor, the second sensor, and the motor, and configured to control the motor based on sensor measurements of the first sensor and the second sensor.

A screw compressor (10) comprising a compressing device (18), in particular, at least one screw-type rotor (20, 22), which feeds a compressed medium to an oil separation device (30). The oil separation device has a first volume (32), a second volume (34) and a separating device (36) that separates the first volume (32) and the second volume (34) from one another. The separating device (36) includes a demister (38) that is located in a first region of the separating device (36). A second region of the separating device (36) is designed as a partition (40) that has one or more oil communication openings (42).

A screw compressor (10) comprising a compressing device (18), in particular, at least one screw-type rotor (20, 22), which feeds a compressed medium to an oil separation device (30). The oil separation device has a first volume (32), a second volume (34) and a separating device (36) that separates the first volume (32) and the second volume (34) from one another. The separating device (36) includes a demister (38) that is located in a first region of the separating device (36). A second region of the separating device (36) is designed as a partition (40) that has one or more oil communication openings (42).

A rotary piston compressor is disclosed, comprising a housing having an epitrochoidal shaped inner bore, peripheral inlet and exhaust ports located in the bore, and a rotary piston rotatably mounted within the housing. The central portion of each rotary piston flank is configured such that, at the closest point between the flank central portion and the housing between the exhaust port of the trailing compression cycle and the inlet port of the leading compression cycle, the radial spacing between the rotary piston flank and the housing is maintained such that the volumes enclosed by the rotary piston on either side of the closest point in the respective trailing and leading compression cycles are substantially sealed from one another. The end portions of each rotary piston flank are configured such that radial spacing between the rotary piston flank and the housing exceeds that between the central portion and the housing.

A rotary piston compressor is disclosed, comprising a housing having an epitrochoidal shaped inner bore, peripheral inlet and exhaust ports located in the bore, and a rotary piston rotatably mounted within the housing. The central portion of each rotary piston flank is configured such that, at the closest point between the flank central portion and the housing between the exhaust port of the trailing compression cycle and the inlet port of the leading compression cycle, the radial spacing between the rotary piston flank and the housing is maintained such that the volumes enclosed by the rotary piston on either side of the closest point in the respective trailing and leading compression cycles are substantially sealed from one another. The end portions of each rotary piston flank are configured such that radial spacing between the rotary piston flank and the housing exceeds that between the central portion and the housing.

Method for preventing condensate in the oil of an oil-injected compressor (1), characterised in that before the compressor element (2) is stopped, when the maximum pressure (pmax) in the consumer network (16) has been reached, the compressor element continues to be driven until the temperature (T) of the oil or the compressed gas is lower than a set fixed or calculated minimum value (Tmin) above which there is no or as little condensate as possible in the oil.

Method for preventing condensate in the oil of an oil-injected compressor (1), characterised in that before the compressor element (2) is stopped, when the maximum pressure (pmax) in the consumer network (16) has been reached, the compressor element continues to be driven until the temperature (T) of the oil or the compressed gas is lower than a set fixed or calculated minimum value (Tmin) above which there is no or as little condensate as possible in the oil.

A compressor includes: a casing with an inner wall defining a compression chamber, an inlet leading into the compression chamber, and an outlet leading out of the compression chamber; a rotor rotatably coupled to the casing for rotation relative to the casing; and a gate coupled to the casing for movement relative to the casing. The gate may be pivotally, or translationally coupled to the casing. A hydrostatic bearing may be disposed between the gate and casing. A plurality of compressors may be mechanically linked together such that their compression cycles are out of phase.

A vacuum pumping system includes an oil-lubricated vacuum pump, including a stationary pump stator and a rotatable pump rotor, and a motor, including a stationary motor stator and a rotatable motor rotor cooperating with each other for driving in rotation the pump rotor. The motor further includes an oil-tight unit including a metal jacket enclosing the motor rotor and forming a container intended to collect and keep inside the motor any oil leaking from the pump.

The oil-free screw compressor includes: a casing having a rotor chamber; a bearing supporting rotary shafts of screw rotors; a shaft seal device with an oil seal portion and an air seal portion; a ventilation gap positioned between the oil seal portion and the air seal portion; and an atmosphere open passage communicating an atmosphere side of the casing with the ventilation gap communicate. A most narrowed portion, an air seal portion, and oil seal portions are set such that the followings is established:
(La/Sa.sup.2.5)/(Lh/Sh.sup.2.5)>|P2|/Pb La: effective shaft seal length Sh: effective open cross-sectional area (most narrowed portion of atmosphere open passage) Lh: effective narrowed length (most narrowed portion of atmosphere open passage) Sa: shaft seal cross-sectional area |P2|: negative pressure in rotor chamber during unloading operation Pb: minimum differential pressure in the oil seal portion during the unloading operation.