Abstract: A first compressor (10) supplies air under pressure to a first stage pressure swing adsorption system (D) which separates oxygen and argon from atmospheric air. A second stage pressure swing adsorption system (E) separates the oxygen from the argon. Each time the compressor (10) is shut off, pressure in molecular sieve beds (22a, 22b) and (90a, 90b) tend to equalize causing mixing of retained primary product gas a feed stock gas. When the compressor (10) is restarted, the intermixed gas is supplied with the primary product gas for the first few cycles. During the first few cycles, a diverter valve (130) diverts the primary product gas to a vent (132) such that the reduced purity primary product gas is not supplied downstream. Thereafter, primary product gas is drawn into a suction tank (110) which is maintained at a reduced pressure by a second compressor (112).

Abstract: A first separation stage (A) separates nitrogen, carbon dioxide, and water vapor from atmospheric air. A mixture of oxygen and argon is passed from the first separation stage as the feed stock to a second separation stage (B). The second separation stage includes a pair of molecular sieve beds (90a, 90b) which adsorb oxygen and pass argon. The feed stock is passed to one of the beds such that the oxygen is adsorbed and the argon flows through to an argon discharge port (96). When the first bed is reaching saturation, a secondary product valve (108) closes the argon discharge port, a flush valve (82) supplies high purity oxygen to the bed, and a product conservation valve (104) causes the oxygen and argon gas in the interstitial voids of the saturated bed to be channeled to the other bed. The other bed is at reduced pressure by virtue of having just had its adsorbed oxygen desorbed.

Abstract: Improved operating efficiency is achieved in a PSA gas concentrator by connecting the primary product gas outlet end of a pressurized sieve bed with a gaseous mixture receiving end of a second molecular sieve bed between each pressure reversal portion of a PSA gas separation cycle. A cross over valve (12) has a first mode (12a) in which a first bed (16) is connected to a source (10) of pressurized air and a second bed (18) is connected with an exhaust port (14), a second mode (12b) in which the second bed is connected with the source of pressurized air and the first bed is connected with the exhaust port, and a third mode (12c) in which the passage of gas between the pressurized air source, the exhaust port, and the first and second beds is prohibited. Check valves (50a, 50b, 50c, and 50d) and a pressure equalization valve (52) selectively interconnect second ends (22, 26) of one bed with the first ends (20, 24 ) of the other.

Abstract: A valve assembly (B) cycles compressed gas from a compressor (A) to a pair of molecular sieve beds (C) to perform a pressure swing adsorption gas separation cycle. Each bed includes a peripheral outer wall (20) and has a tubular member (30) extending down a central axis thereof. An extensible sleeve (26) surrounds the central tube and is in fluid communication therewith by way of an aperture (32). A fluid amplifier (F) amplifies fluid pressure from system gases, particularly the gases from the compressor, and uses the amplified pressure to expand the extensible sleeve. Particles (22) of zeolite material are inhibited from becoming fluidized and moving with fluid flows by the clamping pressure between the extensible sleeve and the peripheral wall of the bed.

Abstract: A cross over valve (46) cyclically supplies air from a compressor (30) to a first bed (48). The first bed contains a material, such as a 5 angstrom zeolite, which preferentially adsorbs nitrogen and passes oxygen and argon therethrough. The oxygen and argon mixture is passed to an oxygen/argon receiving reservoir (60). As the cross over valve flushes nitrogen from the first bed, a pumping fluid under pressure is fed into a pressurizing fluid receiving region (66) to pump the oxygen/argon mixture into a second bed (80). The second bed contains a material, such as 4 angstrom zeolite, which passes nitrogen and argon therethrough and which preferentially adsorbs oxygen. The argon, and the nitrogen if any, are discharged through a secondary gas outlet (22) and the oxygen is adsorbed. The adsorbed oxygen is drawn from the second bed by an enriched oxygen pump (90) and pumped periodically into an enriched oxygen storage reservoir (100).

Abstract: A compressor (10) and an accumulator tank (12) supply compressed air to an oxygen concentrator (32). Separated oxygen flows through a first check valve (40) into a first oxygen receiving region (54) of a first tank (50) displacing a first movable barrier (52). When a pressure sensor (72) senses that the pressure in the first oxygen receiving region has reached a preselected level, it causes a valve (62) to move from a vent state to a state in which compressed air is supplied from the accumulator into a pressurizing fluid receiving region (56). This displaces the first movable barrier with a first preselected pressure, pumping the oxygen through a second check valve (80) into a second oxygen receiving region (94) of a second tank (90). A second movable barrier (92) separates the second oxygen receiving region from a second pressurizing fluid receiving region (96).