Oxygen concentration process

Claim 1

IN A HEATLESS FRACTIONATION PROCESS FOR INCREASING THE CONCENTRATION OF OXYGEN IN A FEED AIR STREAM BY FLOWING AN AIR STREAM INTO AN ADSORPTION ZONE WHREIN A BED OF ADSORBENT SELECTIVELY ADSORBS NITROGEN, MOISTURE, AND CO2 COMPONENTS FROM SAID AIR STREAM AT A RELATIVELY GIGH PRESSURE OF ABOUT 30 P.S.I.G. UP TO 200 P.S.I.G. DURING AN ADSORPTION STEP AND WITHDRAWING FROM SAID ZONE A PRODUCT STREAM OF REMAINING UNADSORBED COMPONENTS OF THE AIR THUS HAVING SUBSTANTIALLY INCREASED OXCYGEN CONCENTRATION, SAID ADSORPTION STEP BEING CARRIED OUT FOR A TIME SUBSTANTIALLY SHORT OF SATURATIO OF THE ADSORBENT BY ADSORBED COMPONENTS THEN BEING FOLLOWED BY A DESORPTION OF THE ADSORBED COMPONENTS AT A RELATIVELY LOW PRESSURE SHORT OF COMPLETE REMOVAL OF THE ADSORBED COMPONENTS, THE STEPS OF ADSORPTION AND DESORPTION BEING CARRIED OUT IN A RAPID MANNER THAT ELIMINATES NEED FOR ADDITION OF EXTERNALLY SUPPLIED HEAT, SO THAT THE ZONE IS AT AMBIENT ATMOSPHERIC TEMPERATURES, THE IMPROVEMNT WHICH COMPRISES PURGING DESORBED COMPONENETS FORM THE BED OF ADSORBENT AT SAID RELATIVELY LOW PRESSURE WITH DRY AIR HAVING A DEW POINT LESS THAN 0*F. AND HAVING A NITROGEN-TOOXYGEN MOLE RATION THE SAME AS ATMOSPHERIC AIR IN SAID FEED STREAM SAID DRY AIR BEING MADE TO FLOW IN A REVERSE DIRECTION FROM THAT OF THE AIR STREAM IN THE ADSORPTION STEP, AND THE FURTHER IMPROVEMENT WHREIN SAID ADSORPTION ZONE IS DEPRESSURED BY PUTTING IT INTO FLUID COMMUNICATION WITH A SECOND ADSORPTION ZONE WHICH HAS HAD DESORED COMPONENTS PURGED BY THE DRY AIR SO THAT GAS FLOWS FROM THE FIRST ADSORPTION ZONE INTO SAID SECOND ADSORPTION Z ONE, THEN FURTHER DEPRESSURING SAID FIRST ADSORPTION ZONE TO SAID RELATIVELY LOW PRESSURE UNDER WHICH SAID PURGING WITH THE DRY AIR IS EFFECTED.