Pressure swing adsorption process for a medical oxygen generator for home use

Claim 1

In the generation and recovery of high purity oxygen from an ambient air stream in a system employing a single adsorption column, the method which comprises the successive steps of: (a) introducing pressurized air into the column containing an adsorbent bed, said bed comprising in the direction of air flow thereinto a first shallow layer of an adsorbent effective in removal of water and CO 2 followed by a predominant second layer of an adsorbent selective in sorbing nitrogen from admixture with oxygen; said bed having been brought to adsorption pressure prior to said initial air introduction with a previously obtained product stream of high oxygen concentration to bring the same form subatmospheric to slightly above atmosphere pressure; (b) continuing said introduction of pressurized air into said bed without withdrawal of product therefrom until said bed is brought to a maximum pressure of several atmospheres; (c) then discontinuing said introduction of pressurized air and withdrawing from said bed, in the same direction as that in which the feed air was introduced, a part of the gas product contained therein and collecting said withdrawn part in a storage reservoir; (d) thereafter venting the bed to the atmosphere in a direction counter to air feed direction, thereby removing a portion of the contained nitrogen from said second adsorbent layer and part of the contained water and CO 2 from said first adsorbent layer; (e) next evacuating the bed in the same direction as in the preceding venting step (d) to remove remaining nitrogen, water and CO 2 from the respective adsorbent layer; followed by, (f) restoring the bed to slightly above atmospheric pressure for repetition of the defined sequence by introducing therein a portion of the product gas of high oxygen concentration from said storage reservoir.