A scroll compressor is provided that can prevent liquid from being accumulated with a simple structure.

The scroll compressor includes: a fixed scroll 11; an orbiting scroll 12; and a rotation shaft 13 that extends in the horizontal direction and causes the orbiting scroll 12 to orbit relative to the fixed scroll 11, and liquid is injected to a working chamber at an intake process or to the upstream side thereof. An enclosing point P of a working chamber formed near the outer end of a fixed wrap 16 of the fixed scroll 11 is positioned below a center O of the rotation shaft 13 and at the lowest point of the contour of the working chamber having shifted to the lowest position. The fixed scroll 11 has an inclined wall surface 33 that is positioned below the center 0 of the rotation shaft 13, is made to face upward, and extends from the dust wrap 17 to the outer end of the fixed wrap 16. The inclined wall surface 33 is formed so as to be sloped down gradually from the dust wrap 17 toward the outer end of the fixed wrap 16.

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.

Disclosed is a safety-reinforced water-ring vacuum pump including a built-in hogging flow path. The water-ring vacuum pump includes a first-stage body, a second-stage body, and an impeller. The first-stage body includes a gas inlet port through which gas is suctioned and a seal water supply port through which seal water is supplied. The second-stage body includes a mixed fluid outlet port through which a mixed fluid of the gas and the seal water is discharged. The impeller is rotated at high speed by an internal drive shaft penetrating the first-stage body and the second-stage body. The first-stage body has a fluid-mixing space provided therein, the fluid-mixing space having a mixed flow of the gas and the seal water therein. The second-stage body has a fluid guide space and an internal hogging flow path provided therein, the internal hogging flow path communicating with the fluid guide space.

An electric priming pump device detachably couples to a centrifugal water pump on the suction side of the water pump, for priming thereof. The device comprises an enclosure and a base, wherein the enclosure contains a rotary vane peripheral bypass vacuum motor which is pressed against the base to form an air-tight seal. The device generates a vacuum for priming through use of a rotary vane peripheral bypass vacuum motor, which can remove large volumes of air quickly. An opening in the base receives a check valve fitting to protect the motor from water and slows loss of vacuum pressure after use. Additionally, a cone shaped protective cover protects components in the device and provides space for branding or advertisement.

An electric priming pump device detachably couples to a centrifugal water pump on the suction side of the water pump, for priming thereof. The device comprises an enclosure and a base, wherein the enclosure contains a rotary vane peripheral bypass vacuum motor which is pressed against the base to form an air-tight seal. The device generates a vacuum for priming through use of a rotary vane peripheral bypass vacuum motor, which can remove large volumes of air quickly. An opening in the base receives a check valve fitting to protect the motor from water and slows loss of vacuum pressure after use. Additionally, a cone shaped protective cover protects components in the device and provides space for branding or advertisement.

An oil-free screw compressor includes: a casing having a rotor chamber; a bearing supporting rotary shafts of the screw rotors; a shaft seal device including an oil seal portion and an air seal portion; an atmosphere open hole formed in the shaft seal device; at least one communication hole formed in the rotary shaft; and an annular space communicating the atmosphere open hole with the at least one communication hole communicate with each other. The annular space includes an inner peripheral annular space formed on an inner peripheral side of the casing. Assuming an open cross-sectional area of the inner peripheral annular space as S1, a total open cross-sectional area of the communication holes as S2, an open cross-sectional area of the i-th communication hole out of the communication holes as S2i, and the number of communication holes as n (n being a natural number of 1 or more), a following relationship is satisfied.

[00001]$S.Math..Math.1\geqq S.Math..Math.2=\underset{i=1}{\overset{n}{.Math.}}.Math..Math.S.Math..Math.2.Math.i$

An oil-free screw compressor includes: a casing having a rotor chamber; a bearing supporting rotary shafts of the screw rotors; a shaft seal device including an oil seal portion and an air seal portion; an atmosphere open hole formed in the shaft seal device; at least one communication hole formed in the rotary shaft; and an annular space communicating the atmosphere open hole with the at least one communication hole communicate with each other. The annular space includes an inner peripheral annular space formed on an inner peripheral side of the casing. Assuming an open cross-sectional area of the inner peripheral annular space as S1, a total open cross-sectional area of the communication holes as S2, an open cross-sectional area of the i-th communication hole out of the communication holes as S2i, and the number of communication holes as n (n being a natural number of 1 or more), a following relationship is satisfied.

[00001]$S.Math..Math.1\geqq S.Math..Math.2=\underset{i=1}{\overset{n}{.Math.}}.Math..Math.S.Math..Math.2.Math.i$

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.

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.

An oil flooded screw compressor includes a housing with an inlet and an outlet, and a rotor supported within the housing by a bearing. The rotor is rotatable to compress air from the inlet to the outlet when the compressor is in an operating state, and the rotor is rotatable without compressing air when the compressor is in an idle state. The compressor also includes a pump configured to supply oil to the bearing only when the compressor is in the idle state.