How do sieve beds generate oxygen?

Sieve beds are the core components of an oxygen concentrator that separate nitrogen from the air to produce medical-grade oxygen. They contain a material called zeolite, which traps nitrogen molecules under pressure while allowing oxygen to pass through. Oxygen concentrators typically use two sieve beds that alternate between concentrating oxygen and releasing the trapped nitrogen, creating a continuous supply of purified oxygen.  

How do sieve beds work?

Air intake:

The concentrator pulls in ambient air, which is about 78% nitrogen and 21% oxygen. 

• Compression:

  An air compressor compresses the air before it is pushed into the sieve beds. 

• Adsorption:

  As the compressed air flows through the sieve beds, the zeolite material selectively adsorbs the nitrogen molecules, trapping them inside the bed. 

• Oxygen delivery:

  The oxygen-rich air, now about 90–95% pure, passes through and is delivered to the user. 

• Regeneration:

  Once the sieve bed is saturated with nitrogen, the process reverses for that bed. The pressure is released, and the trapped nitrogen is expelled back into the atmosphere, resetting the bed to start the cycle again.
  

What is inside a sieve bed?

• Outer shell: usually aluminum or high-grade composite for durability.

• Zeolite material: 13X or Li-based zeolite (Lithium Zeolite) — the key adsorption medium.

• Filters and caps: ensure air purity and prevent dust contamination.

Why are sieve beds important in oxygen concentrators?

• Because they perform the core function — separating nitrogen from air.

  If sieve beds fail, the concentrator cannot produce concentrated oxygen, only regular air.

How long do sieve beds last?

• Depends on usage, humidity, and maintenance.

• High humidity and dust can shorten their life significantly.

What are the signs of a failing sieve bed?

• Oxygen purity drops below 85–90%.

• The concentrator runs longer or cycles more frequently.

• Audible “hissing” or leaks from the bed ends.

• The device triggers a low oxygen alarm.

Can sieve beds be refilled or regenerated?

• Yes, but only under specific conditions:

  • Regeneration involves removing moisture and contaminants by heating under vacuum — best done professionally.

  • Refilling requires new zeolite material and proper sealing — not recommended without precision tools.