Patent ID: 7402193

Claim:
A portable oxygen concentrator, comprising: a plurality of sieve beds adapted to absorb nitrogen from air, each sieve bed comprising an air inlet/outlet end and an oxygen inlet/outlet end; a purge orifice adapted to communicate continuously between the oxygen inlet/outlet ends of a pair of sieve beds in the plurality of the sieve beds; at least one reservoir communicating with the oxygen inlet/outlet ends of the plurality of sieve beds for storing oxygen exiting from the oxygen inlet/outlet ends of the plurality of sieve beds; a compressor for delivering air at one or more desired pressures to the air inlet/outlet ends of the plurality of sieve beds; a set of valves between the compressor and the air inlet/outlet ends of the plurality of sieve beds; a controller coupled to the valves for selectively opening and closing the valves to alternately charge the plurality of sieve beds by delivering compressed air into the plurality of sieve beds through the air inlet/outlet ends to cause oxygen to exit from the oxygen inlet/outlet ends into the reservoir and purge plurality of the sieve beds by evacuating pressurized nitrogen from the plurality of sieve beds through the air inlet/outlet ends, and wherein oxygen passes from a sieve bed being charged to a sieve bed being purged via the purge orifice to assist evacuating nitrogen from the sieve bed being purged; and an exhaust passage communicating with the air inlet/outlet ends of the plurality of sieve beds, wherein the exhaust passage is configured to deliver a flow of nitrogen evacuated from the plurality such that the flow of the nitrogen is directed at or across the controller to cool the controller.