A fluid pump includes an inlet plate with an inlet; an outlet plate, the outlet plate having an outlet plate outlet passage; an outlet; an electric motor having a shaft which rotates; a pumping element coupled to the shaft such that rotation of the pumping element by the shaft causes fluid to be pumped from the inlet to the outlet, the inlet plate interfacing with the pumping element in an inlet sealing surface interface and the outlet plate interfacing with the pumping element in an outlet sealing surface interface; a purge passage which receives fluid from the outlet plate outlet passage, the purge passage being in fluid communication with the inlet sealing surface interface and the outlet sealing surface interface; and a filter downstream of the outlet plate outlet passage which filters fluid that passes through the purge passage prior to reaching the inlet and outlet sealing surface interfaces.

Systems and methods for extracting hydrocarbon gas utilize a vacuum chamber with a mud chamber portion that is expandable and contractible. Gas is extracted at vacuum pressures.

The invention concerns a method and an apparatus for operating a multi-phase pump which has a suction-side inlet (10) and a discharge-side outlet (20) and which pumps a multi-phase mixture charged with solids, comprising the following steps:

a. pumping a multi-phase mixture into a discharge-side separation chamber (45),

b. separating a gaseous phase from a liquid phase and a solid phase in the separation chamber (45),

c. separating the liquid phase from the solid phase in the separation chamber (45), and

d. supplying a portion of the liquid phase freed from the solid phase to the suction side.

The invention concerns a method and an apparatus for operating a multi-phase pump which has a suction-side inlet (10) and a discharge-side outlet (20) and which pumps a multi-phase mixture charged with solids, comprising the following steps: a. pumping a multi-phase mixture into a discharge-side separation chamber (45), b. separating a gaseous phase from a liquid phase and a solid phase in the separation chamber (45), c. separating the liquid phase from the solid phase in the separation chamber (45), and d. supplying a portion of the liquid phase freed from the solid phase to the suction side.

Provided is a hydraulic circuit for transmissions with which, while suppressing the hydraulic circuit from becoming complicated, it is possible to suppress an operational failure and a drop in the oil pressure of the hydraulic circuit, and to stabilize an oil pressure in the hydraulic circuit. The CVT 1 includes a part to be lubricated and a hydraulic control part for controlling transmission. The hydraulic circuit for transmissions includes a hydraulic oil pathway 3 for supplying oil from the pump apparatus 8 to the hydraulic control part 2, and a lubricating oil pathway 5 for supplying oil containing an air bubble to the part to be lubricated 4. The pump apparatus 8 includes a multi-stage trochoid pump 9 and has an air bubble-containing oil discharging part 11 for discharging the oil containing an air bubble to the first stage trochoid pump part 6. The air bubble-containing oil discharging part 11 is connected to the lubricating oil pathway 5. The second stage trochoid pump part 7 increases pressure of the oil discharged from the first stage trochoid pump part 6, and discharges it from the high-pressure oil discharging part 13. The hydraulic oil pathway 3 is connected to the high-pressure oil discharging part 13.

A multiphase pump system includes a pump (10) having first and second screw rotors (4) disposed within a pump body (A), and at least one inlet (3) in fluid communication with the first and second screw rotors, respectively. A discharge casing (B) is coupled to the pump body (A) for receiving fluid discharged from the first and second screw rotors (4). The discharge casing (B) is oriented orthogonally or at a non-zero angle with respect to a longitudinal axis of the pump body (A). The discharge casing (B) includes a separation chamber for separating liquid and gas components of the fluid discharged from the first and second screw rotors (4). The pump body (A) includes at least one opening (9) for directing separated liquid from the discharge casing (B) to a discharge chamber of the pump body (A).