Various downhole tools are discussed, including intake and gas separators for a downhole rotary pump. Multiple intakes configured in parallel and series are discussed, along with compact axial length gas separators, and gas separators that remove gas in novel ways. Related apparatuses and methods are discussed.

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.

Various downhole tools are discussed, including intake and gas separators for a downhole rotary pump. Multiple intakes configured in parallel and series are discussed, along with compact axial length gas separators, and gas separators that remove gas in novel ways. Related apparatuses and methods are discussed.

An aero-engine low pressure pump is provided for supplying fuel at a raised pressure to a high pressure pump. The low pressure pump has a pumping mechanism which raises the pressure of fuel flowing though the mechanism. The low pressure pump further has electrical motor which drives the pumping mechanism. The low pressure pump further has a variable frequency motor drive which supplies electrical power to the electrical motor. The variable frequency motor drive measures the electrical power supplied to the electrical motor. The low pressure pump further has a control unit which compares the measured electrical power to a reference power, and, when the measured electrical power is less than the reference power by a predetermined amount, controls the motor drive to increase the power supplied to the electrical motor thereby increasing the pressure rise produced by the pumping mechanism.

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.

The gas compression method/system restricts flow of emulsified liquid-gas mixture through many substantially radial capillary tube-passages in a rotating disk by either one-way valves, narrowing the passages, hydraulic impedance and/or reinforcement of coriolis forces in terminal end tail segments of the capillary passages. Compressed gas is released from peripherally collected compressed gas-liquid emulsion (beyond the terminal ends of the tubes) in a arcuate peripheral disc space when the compressed gas bubbles emerge from the peripherally collected emulsion. A compressed gas drain draws off gas from the peripheral space. Liquid drain draws off liquid from the space. In different embodiments, radial outboard flow through the capillaries is effected by various one-way valves which may be a single valve in the passage or multiple valves. Coriolis force in tail segments is enhanced by angular displacement in the direction of rotation. Valves may be used in combination with such tail-end segments.

An aero-engine low pressure pump is provided for supplying fuel at a raised pressure to a high pressure pump. The low pressure pump has a pumping mechanism which raises the pressure of fuel flowing though the mechanism. The low pressure pump further has electrical motor which drives the pumping mechanism. The low pressure pump further has a variable frequency motor drive which supplies electrical power to the electrical motor. The variable frequency motor drive measures the electrical power supplied to the electrical motor. The low pressure pump further has a control unit which compares the measured electrical power to a reference power, and, when the measured electrical power is less than the reference power by a predetermined amount, controls the motor drive to increase the power supplied to the electrical motor thereby increasing the pressure rise produced by the pumping mechanism.

A pump has a brushless electrical motor including a stator assembly and a rotor ring arranged externally of the stator assembly. The pump further has a centrifugal impeller operatively connected to the rotor ring such that the electrical motor rotates the impeller. The impeller is configured to raise the pressure of a fluid which flows through the impeller between an inlet and an outlet thereof. The pump is configured such that a portion of the raised pressure fluid flow is diverted to form a recirculation flow which circulates through and cools the electrical motor before being returned to the impeller for re-pressurisation thereby.

The compressor compresses gas in capillaries leading to a radially distant annular container space. Centrifugal force acts on gas bubbles entrained between liquid slugs moving radially outward through the capillaries which may be radial, tangential or continuously curved. Compressed gas is collected in the annular space. A gas-liquid emulsion is fed to the capillaries by an inboard emulsification device. The emulsification may include a vortex generator, an ejector or a venturi injector, all feeding the gas-liquid mixture into the inboard ends of the capillaries. The capillaries are formed in a series of discs, coaxially stacked with outer disc ends open to the annular space. Capillary inlets may be perpendicular, tangential or may define a venturi jet.