….People keep asking me this question….
Therefore, because, unlike my Father, Sister and Brother, I am not a scientist, and unlike Julian, I am not an Engineer, I have trawled the web and found this which makes it pretty understandable even for a little blonde thing like me!
network of tiny holes, zeolite resembles a miniature Swiss cheese, and presents an enormous amount of surface area on which gas molecules can adsorb. Nitrogen molecules stick more often to zeolite than oxygen molecules because
nitrogen molecules bind more strongly to the zeolite surface than do oxygen molecules. Zeolites tend to concentrate oxygen in the air by removing most of the nitrogen molecules. An oxygen concentrator takes in room air, passes the air through a filter to remove any dust particles and raises the air to a pressure of 20 pounds psi by a compressor (see
Figure 1). To extract as much nitrogen as possible, the pressurized air is pumped into a canister containing zeolite (often called “sieve bed”). The zeolites adsorb most of the nitrogen from this air, leaving nearly pure oxygen forbreathing. After about 20 seconds, the zeolites become saturated with nitrogen and cannot extract any more. At this point, a solenoid valve opens to reduce the pressure on the canister to atmospheric pressure, and the nitrogen begins to be released prior
to beginning another cycle. This canister switching process is under electronic control. Some oxygen concentrators employ microprocessors and actual oxygen sensing circuitry that monitors the oxygen percentage in the air and detects when the output gets too low. To keep oxygen flowing at all times, a typical oxygen concentrator has two separate
zeolite-filled canisters. At any given time, one canister is providing oxygen for breathing, while the other is regenerating by releasing its stored nitrogen into the air.
….That made fun reading, huh!