Rotary pressure transfer device

A pressure transfer device for transferring pressure energy from a high pressure first liquid to a lower pressure second liquid to provide a pressurized second liquid, which device comprises:

• a rotatably mounted cylindrical rotor having a pair of opposite planar end faces with a plurality of channels extending axially therethrough between openings located in said planar end faces;
• a pair of opposite end covers having axially inward and outward end surfaces and having inlet and discharge passageways, said axially inward end surfaces of each end cover having flat regions that interface with and slidingly and sealingly engage said respective planar end faces of said rotor, said inlet and discharge passageways connecting to openings in said axially inward end surfaces, and said end covers being aligned so that when one said channel in said rotor is aligned with one said inlet passageway opening in one said end cover, it is also aligned with one said discharge passageway opening in said opposite end cover, said inlet passageway openings and each said discharge passageway openings in said same end cover being constantly sealed from one another during the operation by a sealing region at an interface between said rotor planar end face and said end cover;
• and
• a stator that is interconnected with both said end covers about which said rotor revolves,
• said stator having two spaced apart lateral bearing surfaces, with a circumferential groove therebetween which will hold a reservoir of liquid for lubricating said bearing surfaces, having a supply passageway which extends generally radially inward from said groove, and having a branch passageway which connects said supply passageway to an interior region of high pressure liquid within the pressure transfer device,
• whereby during revolution of said rotor said rotor channel openings are, in alternating sequence, brought into full alignment with both an inlet passageway opening in one said end cover and a discharge passageway opening in the opposite said end cover and then into full alignment with both a discharge passageway opening in said one end cover and an inlet passageway opening in said opposite end cover, at least twice during each revolution of said rotor, so that each said channel is at least twice supplied with the high pressure first liquid and at least twice discharges pressurized second liquid.

A method for transferring pressure energy from a high pressure first liquid to a lower pressure second liquid to provide a pressurized second liquid, which method comprises the steps of:

• rotatably mounting a cylindrical rotor in a housing, which rotor has a pair of opposite planar end faces and has a plurality of channels extending longitudinally therethrough between openings located in said planar end faces;
• disposing a pair of opposite end covers in the housing having axially inward surfaces with flat surface regions so that their axially inward end surfaces interface with and slidingly and sealingly engage said planar end faces of said rotor, which end covers each have a plurality of inlet passageways and a plurality of discharge passageways which open into said flat surface regions in openings of substantially the same size,
• supplying a high pressure first liquid to said inlet passageways in one end cover while simultaneously discharging a pressurized second liquid from said aligned discharge passageways in the end cover at the opposite end, and
• causing said rotor to revolve about its axis so said channels are respectively brought into full alignment with one of said inlet passageway openings in one end cover and one of said discharge passageway openings in the other end cover at least twice during each revolution of the rotor, whereby an increased volume of pressurized second liquid is discharged for each revolution of the rotor because each channel is supplied with liquid and discharged at least twice.