Method and apparatus for concentrating oxygen

In the method of concentrating oxygen, utilizing the steps of pumping air through one zeolitic bed while purging and exhausting air from a second zeolitic bed by venting said second zeolitic bed to the atmosphere from one end and directing a portion of oxygen-enriched air from said first bed into the opposite end of said second bed and vice versa in sequential steps, the improvements comprising the steps of pumping and flowing the air isothermally into said beds through conduits and valves, all of which have no restrictions in cross-sectional area therethrough from the air pump to the beds.

Air pump apparatus for pumping air comprising:

• an internal chamber enclosed by a cylindrical liner of circular cross section, an intake port for conducting air into said chamber, an exhaust port for conducting air out of said chamber, and air moving means for moving air from said intake port to said exhaust port, wherein said air moving means includes a rotatable rotor of smaller diameter than said chamber and mounted eccentrically in said chamber, said rotor having a plurality of slots opening therein from the peripheral surface and a vane slideably positioned in each slot, each of said vanes having a tapered trailing side adjacent the distal end portion to reduce wear and erosion of said vanes at the mouths of said slot openings.

Air pump apparatus for moving air, comprising:

• an internal chamber, an intake port for conducting air into said chamber, an exhaust port for conducting air out of said chamber, a rotatable rotor of smaller diameter than said chamber and mounted eccentrically in said chamber, said rotor having a plurality of slots opening therein from the peripheral surface and a vane slideably positioned in each slot, and
• lateral end containers enclosing the ends of said pump chamber and a casing enclosing the ends of said pump chamber and a casing enclosing said liner and said end containers, said liner and said end containers being fabricated of cast iron for low friction and high wear resistance to said vanes and said casing being fabricated of aluminum for reduced weight and increased heat dissipation capacity to enhance the isothermal flow of air therethrough.

In oxygen concentrator apparatus having two beds of zeolitic material, a pump for pumping air into each zeolitic bed, sequencing valves for directing air from the pump first to one of the zeolitic beds while exhausing the other zeolotic bed and vice versa, directional control for delivering oxygen enriched air to a product storage tank while preventing back flow of the oxygen enriched air from the product storage tank to the beds, and a balance valve for directing a portion of the oxygen enriched air from one tank to the other, the improvement comprising:

• a combination flow and balance control valve including a unitary valve body enclosing an interior chamber, three ports extending through said valve body into said chamber, two of said ports being intake ports, each of said intake ports being connected to opposite ones of said beds, and the remaining one of said ports being an outlet port, two flexible membranes mounted in said chamber, each membrane covering a different one of said intake ports and adapted to move away from the port when there is a higher pressure in the port than in the chamber and to move against and seal the port when there is a lower pressure in the port than in the chamber, and a cross-bleed port extending between and connecting said intake ports.