Life support oxygen concentrator

Process for pressure swing adsorption separation of a feed gas mixture containing a more readily adsorbed component and a less readily adsorbed component, with the more readily adsorbed component being preferentially adsorbed from the feed gas mixture by an adsorbent material under increase of pressure, so as to separate from the feed gas mixture a heavy product gas enriched in the more readily adsorbed component and a light product gas enriched in the less readily adsorbed component;

• providing for the process a cooperating set of three adsorbers within a rotor and equally spaced by 120° angular separation about the axis defined by rotation of the rotor relative to a stator, and rotating the rotor so as to generate within each adsorber cyclic variations of pressure and flow at a cyclic period defined by the frequency of rotation along a flow path contacting the adsorbent material between first and second ends of the adsorber, the cyclic variations of pressure extending between a higher pressure and a lower pressure of the process;
• rotating the rotor so that the first ends of the adsorbers successively communicate to feed and exhaust ports provided in a first valve surface between the rotor and the stator, and the second ends of the adsorbers successively communicate to a light product port, to first, second and third light reflux exit ports and to first, second and third light reflux return ports provided in a second valve surface between the rotor and the stator;
• the process including for each of the adsorbers in turn the following cyclical steps in sequence:
• (a) supplying feed gas mixture at a feed pressure through the feed port to the adsorber over a feed interval which is substantially {fraction (1/3)} of the cycle period so as to pressurize the adsorber to substantially the higher pressure, and then to deliver light product gas from the light product port at substantially the higher pressure less flow frictional pressure drops,
• (b) withdrawing a first light reflux gas enriched in the less readily adsorbed component from the first light reflux exit port at about the end of the feed interval,
• (c) withdrawing a second light reflux gas enriched in the less readily adsorbed component from the first light reflux exit port to depressurize that adsorber after the feed interval,
• (d) withdrawing a third light reflux gas enriched in the less readily adsorbed component from the first light reflux exit port to further depressurize that adsorber,
• (e) withdrawing second product gas at an exhaust pressure through the exhaust port from the adsorber over an exhaust interval which is substantially {fraction (1/3)} of the cycle period so as to further depressurize that adsorber to substantially the lower pressure while delivering the second product gas,
• (f) returning third light reflux gas from the third light reflux return port which is receiving that gas after pressure letdown from another adsorber (whose phase is leading by 120°), so as to purge the adsorber in the latter part of the exhaust interval,
• (g) returning second light reflux gas from the second light reflux return port so as to partially repressurize the adsorber prior to the next feed interval,
• (h) returning first light reflux gas from the first light reflux return port which is receiving that gas after pressure letdown from another adsorber (whose phase is lagging by 120°), so as to further repressurize the adsorber prior to the next feed interval, and
• (i) cyclically repeating the above steps,
• so that feed gas is continuously supplied to substantially one adsorber at time, and exhaust gas is continuously removed from substantially one adsorber at a time.

Process for pressure swing adsorption separation of a feed gas mixture containing a more readily adsorbed component and a less readily adsorbed component, with the more readily adsorbed component being preferentially adsorbed from the feed gas mixture by an adsorbent material under increase of pressure, so as to separate from the feed gas mixture a heavy product gas enriched in the more readily adsorbed component and a light product gas enriched in the less readily adsorbed component;

• providing for the process a cooperating set of three adsorbers, and generating within each adsorber cyclic variations of pressure and flow at a cyclic period defined by the frequency of rotation along a flow path contacting the adsorbent material between first and second ends of the adsorber and with the cyclic phase 120° staggered for each adsorber, the cyclic variations of pressure extending between a higher pressure and a lower pressure of the process;
• the process including for each of the adsorbers in turn the following cyclical steps in sequence:
• (a) supplying feed gas mixture to the first end of the adsorber over a feed interval which is substantially {fraction (1/3)} of the cycle period so as to pressurize the adsorber to substantially the higher pressure, and then to deliver light product gas from the second end of the adsorber at substantially the higher pressure less flow frictional pressure drops,
• (b) withdrawing a first light reflux gas enriched in the less readily adsorbed component from the second end of the adsorber at about the end of the feed interval,
• (c) withdrawing a second light reflux gas enriched in the less readily adsorbed component from the second end of the adsorber to depressurize that adsorber after the feed interval, and delivering the second light reflux gas to a buffer chamber,
• (d) withdrawing a third light reflux gas enriched in the less readily adsorbed component from the second end of the adsorber to further depressurize that adsorber,
• (e) withdrawing second product gas at an exhaust pressure from the first end of the adsorber over an exhaust interval which is substantially {fraction (1/3)} of the cycle period so as to further depressurize that adsorber to substantially the lower pressure while delivering the second product gas,
• (f) supplying third light reflux gas from another adsorber (whose phase is leading by 120°) to the second end of the adsorber, so as to purge the adsorber during the latter part of the exhaust interval,
• (g) supplying second light reflux gas from the buffer chamber to the second end of the adsorber, so as to partially repressurize the adsorber prior to the next feed interval,
• (h) supplying third light reflux gas from another adsorber (whose phase is leading by 120°) to the second end of the adsorber, so as to further repressurize the adsorber prior to the next feed interval, and
• (i) cyclically repeating the above steps,
• while feed gas is continuously supplied to substantially one adsorber at time, and exhaust gas is continuously removed from substantially one adsorber at a time.

Apparatus for pressure swing adsorption separation of a gas mixture containing a more readily adsorbed component and a less readily adsorbed component, with the more readily adsorbed component being preferentially adsorbed from the gas mixture by an adsorbent material under increase of pressure between a lower pressure and a higher pressure, so as to separate from the gas mixture a heavy product gas enriched in the more readily adsorbed component and a light product gas depleted in the more readily adsorbed component;

• the apparatus including an adsorber rotor cooperating with a stator mutually defining the rotational axis of the rotor and with rotor drive means to rotate the rotor at a rotational period which defines a pressure swing adsorption cycle period, the rotor containing a cooperating set of three adsorbers equally angularly spaced about the rotational axis, each adsorber having a flow path contacting the adsorbent material between first and second ends of the adsorber, the first ends of the adsorbers communicating by first apertures to a first valve surface between the rotor and the stator, and the second ends of the adsorbers communicating by second apertures to a second valve surface between the rotor and the stator;
• the first valve surface having feed and exhaust ports engaging successively in fluid communication with the first apertures, and the first valve surface having a light product port, and first, second and third light reflux exit ports and first second and third light reflux return ports engaging successively in fluid communication with the second apertures;
• the apparatus further including feed supply means communicating to the feed port and second product exhaust means communicating to the exhaust port;
• the first and third light reflux exit ports communicating to directly to the first and third light reflux return ports respectively, and the second light reflux exit port communicating to a buffer chamber communicating in turn to the second light reflux return port;
• and the angular positions and widths of the ports and apertures being configured so that for each adsorber in sequence the following steps are performed:
• (a) the first aperture of the adsorber is opened to the feed port through which feed gas mixture is supplied by the feed supply means over a feed interval of substantially {fraction (1/3)} of the cycle period so as to pressurize the adsorber to substantially the higher pressure, while the second aperture of the adsorber is then opened to the light product port in the feed interval so as to deliver light product gas at substantially the higher pressure less flow frictional pressure drops,
• (b) the second aperture of the adsorber is opened sequentially to the first, second and third light reflux exit ports so as to deliver light reflux gas enriched in the less readily adsorbed component and to depressurize the adsorber after the feed interval,
• (c) the first aperture of the adsorber is opened to the exhaust port through which second product gas is exhausted by the second product exhaust means at an exhaust pressure over an exhaust interval which is substantially {fraction (1/3)} of the cycle period so as to depressurize that adsorber to substantially the lower pressure and to deliver the second product gas,
• (d) the second aperture of the adsorber is opened sequentially to the third, second and first light reflux return ports so as to purge the adsorber in the latter part of the exhaust interval and then to partially repressurize the adsorber prior to the next feed interval.

Process for pressure swing adsorption separation of a feed gas mixture containing a more readily adsorbed component and a less readily adsorbed component, with the more readily component being preferentially adsorbed from the feed gas mixture by an adsorbent material under increase of pressure, so as to separate from the feed gas mixture a heavy product gas enriched in the more readily adsorbed component and a light product gas enriched in the less readily adsorbed component;

• providing for the process a co-operating set of three adsorbers within an adsorber housing body (AHB) and equally spaced angularly about the axis defined by relative rotation between the AHB and first and second valve bodies relative to a stator, and establishing relative rotation so as to generate within each adsorber cyclic variations of pressure and flow at a cyclic period defined by the frequency of rotation along a flow path contacting the adsorbent material between first and second ends of the adsorber, the cyclic variations of pressure extending between a higher pressure and a lower pressure of the process;
• establishing the relative rotation so that the first ends of the adsorbers successively communicate to feed and exhaust ports provided in a first valve surface between the AHB and the first valve body, and the second ends of the adsorbers successively communicate to a light product port, to light reflux exit ports and to light reflux return ports provided in a second valve surface between the AHB and the second valve body;
• the process including for each of the adsorbers in turn:
• (e) supplying feed gas mixture at a feed pressure through the feed port to the adosrber over a feed interval which is substantially {fraction (1/3)} of the cycle period so as to pressurize the adsorber to substantially the higher pressure, and then to deliver light product gas from the light product port at substantially the higher pressure less flow frictional pressure drops;
• (f) withdrawing light reflux gas enriched in the less readily adsorbed component from the light reflux exit ports, in part to depressurize that adsorber after the feed interval;
• (g) withdrawing second product gas at an exhaust pressure through the exhaust port from the adsorber over an exhaust interval which is substantially {fraction (1/3)} of the cycle period so as to depressurize that adsorber to substantially the lower pressure while delivering the second product gas;
• and
• (h) returning light reflux gas enriched in the less readily adsorbed component from the light reflux return ports so as to purge the adsorber in the latter part of the exhaust interval and then to partially repressurize the adsorber prior to the next feed interval, so that feed gas is continuously supplied to substantially one adsorber at time, and exhaust gas is continuously removed from substantially one adsorber at a time.