A gear pump comprises an internal gear (10), a first external gear (20) and a second external gear (30), a case member (50) having a one end side accommodation portion (52) for retaining these gears (10,20,30), an other end side accommodation portion (53) at other end side and a partition wall portion (54) therebetween, a cover member (70) and a plate member (80). A pump chamber (P) defined inside the internal gear (10) is divided into a first pump chamber (P1) which has a first intake-discharge space (L1) and a first discharge-intake space (H1), and a second pump chamber (P2) which has a second intake-discharge space (L2) and a second discharge-intake space (H2). The plate member has a first communication path (81) and a second communication path (82) between the plate member (80) and the cover member (70). The one side communication passage (57) is communicated with the first communication path (81). Two penetrating holes (82b,82c) are formed on the plate member (80). An other side communication passage (82a), which communicate the two penetrating holes (82b,82c) with each other, is formed between the plate member (80) and the cover member (70).

A liquid ring pump manifold comprising at least one integrated spray nozzle, the at least one integrated spray nozzle being configured to spray a liquid into the liquid ring pump manifold. The liquid ring pump manifold may comprise at least one socket in which the at least one integrated spray nozzle is accommodated. The at least one socket may be integrally formed with the liquid ring pump manifold.

Overheating of a process liquid retained in a reservoir of a multiphase pump during extended gas slugs is avoided by circulating a cooling liquid in thermal contact with a process liquid through an external cooling apparatus, which can include a heat exchanger. In some embodiments, process liquid from the reservoir is circulated through the cooling loop, while in other embodiments a separate cooling liquid is circulated between a reservoir heat exchanger and the external cooling apparatus. The liquid in the cooling loop can be circulated by a separate cooling pump, or process liquid can be circulated through the cooling loop due to a pressure differential between an inlet and an outlet of the cooling loop within the multiphase pump. The multiphase pump can be a twin screw pump, and the reservoir can be formed between outer and inner casings of the multiphase pump.

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; one or more regulating devices configured to control flow of the operating liquid into 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 an operating liquid received by the liquid ring pump; and a controller operatively coupled to the sensors and the regulating device(s), and configured to control the regulating device(s) based on measurements by the sensors.

A system comprising: a suction line; a liquid ring pump coupled to the suction line, the liquid ring pump comprising a chamber and an impeller mounted within the chamber; a non-return valve arranged to permit fluid to flow into the chamber via the suction line and to prevent or oppose fluid flow out of the chamber to the suction line; a gas line coupled to the liquid ring pump such that a gas may flow into the liquid ring pump via the gas line, the gas line coupled to the liquid ring pump between the non-return valve and the chamber; a valve disposed on the gas line; and a controller configured to control the valve.

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 gear pump comprises an internal gear (10), a first external gear (20) and a second external gear (30), a case member (50) having a one end side accommodation portion (52) for retaining these gears (10,20,30), an other end side accommodation portion (53) at other end side and a partition wall portion (54) therebetween, a cover member (70) and a plate member (80). A pump chamber (P) defined inside the internal gear (10) is divided into a first pump chamber (P1) which has a first intake-discharge space (L1) and a first discharge-intake space (H1), and a second pump chamber (P2) which has a second intake-discharge space (L2) and a second discharge-intake space (H2). The plate member has a first communication path (81) and a second communication path (82) between the plate member (80) and the cover member (70). The one side communication passage (57) is communicated with the first communication path (81). Two penetrating holes (82b,82c) are formed on the plate member (80). An other side communication passage (82a), which communicate the two penetrating holes (82b,82c) with each other, is formed between the plate member (80) and the cover member (70).

The present invention relates to a two-stage liquid ring vacuum pump in which two-stage impellers are attached to an axial end portion of a main shaft (rotating shaft) of a motor. The two-stage liquid ring vacuum pump includes a first-stage impeller (4) provided in a first-stage pump chamber (1), a second-stage impeller (5) provided in a second-stage pump chamber (2), a single rotating shaft (7) to which the first-stage impeller (4) and the second-stage impeller (5) are fixed, and an exhaust port (Pd) of the first-stage pump chamber (1) and an intake port (Ps) of the second-stage pump chamber (2) which communicate with each other. An outer diameter of the first-stage impeller (4) is larger than an outer diameter of the second-stage impeller (5).

A fluid ring compressor comprises a first single-acting compression stage having a first impeller eccentrically mounted in a housing and a second single-acting compression stage having a second impeller eccentrically mounted in a housing. The first compression stage and the second compression stage are separated from one another by a sealing gap. The sealing gap is arranged between a suction section of the first compression stage and a suction section of the second compression stage.

Overheating of a process liquid retained in a reservoir of a multiphase pump during extended gas slugs is avoided by circulating a cooling liquid in thermal contact with a process liquid through an external cooling apparatus, which can include a heat exchanger. In some embodiments, process liquid from the reservoir is circulated through the cooling loop, while in other embodiments a separate cooling liquid is circulated between a reservoir heat exchanger and the external cooling apparatus. The liquid in the cooling loop can be circulated by a separate cooling pump, or process liquid can be circulated through the cooling loop due to a pressure differential between an inlet and an outlet of the cooling loop within the multiphase pump. The multiphase pump can be a twin screw pump, and the reservoir can be formed between outer and inner casings of the multiphase pump.