Frequently Asked Questions
We have tried to answer as many of the most frequently asked questions as possible or refer you to other sources of information that may help.
If you have a question that is not shown here please contact us.
What are nitrogen generators?
Nitrogen generators are a piece of equipment which supply a constant flow of
gaseous nitrogen at purities up to 99.9995%
How do they work?
The air around us consists of 78% nitrogen, 21% oxygen, the remainder is made
of carbon dioxide, argon and traces of other gases. Nitrogen generators use a supply
of compressed atmospheric air, and pass this through the generator to strip the
Oxygen from the supply. This leaves you with an output of Nitrogen, and a waste
feed of oxygen enriched air which is vented back into the atmosphere.
Are there different types of generators?
There are two types of generator, Membranes and Pressure Swing Absorption (PSA).
PSA generators These use carbon molecular sieve (CMS), which allows the smaller
molecules in the input air (such as oxygen) to penetrate the CMS, whilst the larger
molecules of nitrogen bypass the CMS to generate the output gas. A PSA generator
consists of a pair of columns filled with CMS. PSA generators can achieve
higher purity levels than membrane systems, up to 99.9995%
Membrane Generators These use a bundle of hollow fibres which separate gases
by the principle of selective permeation. A membrane generator consists of these
hollow fibres, encased within an outer shell of GRP. The faster permeating gases
diffuse quickly through the membrane wall, leaving an output of nitrogen up to 99.9%
pure. These systems are very compact and robust.
What are the key benefits of nitrogen generators compared to delivered gas?
- You save up to 80% on the cost of the nitrogen you use compared to buying in nitrogen
in bulk
- Payback is usually under 18 months, and the product has a typical lifespan of over
10 years
- A constant supply ensured: you never have to worry about a delivery not getting
to you in time again
- Save space & minimise risk and handling errors: no need for gas bottles/liquid nitrogen
tank in the yard
- Simplify administration to save time & money with no weekly deliveries to manage
- Very low running costs: uses your compressed air supply. Average annual servicing
costs of £150
Are nitrogen generators safe?
Yes. As the generator does not add or take anything away from the atmospheric
air, you could have one running in a closed room with no change to the overall content
of the atmosphere. They also negate the need to store and move potentially dangerous
high pressure cylinders on site.
Will getting a quote mean lots of meetings with engineers, or searching for lots
of facts & figures?
No. In order for us to size & price a system for you, we need 4 things:
- The flow of nitrogen required
- The purity of nitrogen required
- The input pressure of your compressed air supply
- The pressure the nitrogen is used in your application
Why don't more companies have generators?
Traditionally, nitrogen generators were only economically viable in very large
applications. With constant development, today's high efficiency products ensure
that generators are economically viable for the smallest of applications, and an
ever increasing number of companies are moving to generate their own nitrogen.
Can Atlas Copco supply and install a complete nitrogen generation system with compressed air supply?
Yes, Atlas Copco Compressors can handle everything from air intake to nitrogen pipework.