How on-site generation works
A PSA nitrogen generator passes compressed air through a bed of carbon molecular sieve. Oxygen is adsorbed preferentially, nitrogen passes through. Two beds alternate so production is continuous. Nothing is burned and nothing is stored as a cryogenic liquid, which is why on-site generation suits plants that use nitrogen steadily and want to stop paying for delivered gas.
The purity / flow trade-off
For a given bed, asking for higher purity means less nitrogen per unit of compressed air, so flow falls. Our range covers small machines in the 4 to 7.5 kW class up to 132 kW units, with 8 bar as the common feed pressure, and purity requirements commonly quoted from 95% up to 99.99% depending on the application. The number that matters is the purity the process actually needs - food packaging, laser cutting and electronics sit at different points.
| Application | Purity driver |
|---|---|
| Food packaging | Shelf life and oxidation control |
| Laser cutting | Assist gas quality and cut edge |
| Electronics assembly | Oxygen exclusion during soldering or storage |
| Chemical blanketing | Safety and reaction control |
What the system needs around it
- Clean, dry feed air - oil and water poison the sieve; the filter chain is part of the generator, not an option.
- Stable pressure - the cycle depends on it; a receiver upstream smooths demand swings.
- Storage - a nitrogen buffer lets the generator run at its efficient point instead of chasing demand.
- Monitoring - an oxygen analyser on the outlet is the only way to know the bed is still performing.
Delivered gas versus generation
The comparison is between the cost of electricity and maintenance per cubic metre and the delivered cost of cylinders or liquid, including rental, delivery and evaporation losses. Generation usually wins on steady, high-volume use and loses on occasional use - which is exactly the opposite of what most people assume before they run the numbers.
Browse the range on the nitrogen generator collection page.
Tell us the working pressure, flow and site conditions and we will propose a configuration. Contact OPPAIR.