Naturally present in the atmosphere, nitrogen is a gas widely used in many industries areas : laser cutting, Modified Atmosphere Packaging, inerting, etc. It is particularly known for its action against certain tumors, but also as an insecticide and processor cooler. This gas production requires specifical devices. To understand, here what you have to know about nitrogen generator operation.
Nitrogen generator general operation
Ambient air is constituted of 78% nitrogen. To access and exploit this natural resource, it must be isolated from other components of the atmosphere : oxygen, humidity, dust... This is the principle of nitrogen generator, which allows companies to produce on-site the nitrogen they need from ambient air. There are two main types of nitrogen generator : the PSA nitrogen generator and the membrane nitrogen generator.
The PSA nitrogen generator
The PSA generator (for Pressure Swing Adsorption, Separation by Alternate Pressurization) allows to produce nitrogen from ambient air. This device consists of two receivers, filled with molecular sieves (activated carbon). Alternate pressurization of these receivers causes the separation of the different gases (nitrogen, oxygen, argon, rare gases). More specifically, the pressurizatin causes the filtering of nitrogen by the activated carbon. This pure gas is the released at the generator outlet, while oxygen, carbon dioxide or water vaper are adsorbed (are fixed) on the activated carbon. Once the first receiver is saturated, the process continues in the second receiver. The adsorbed gas in the first receiver is then released in the atmosphere. An electronic control allows the repetition of this cycle. When one of the receivers adsorbs, the pressure drops to the other receiver to allow its regeneration.
The membrane nitrogen generator
As the PSA generator, the membrane generator uses the ambient air to produce nitrogen. It works however on a very different process. The membrane generator separates the differet components of the atmosphere using a hollow fiber bundle. Particularly compact, these fibers are present in very wide quantities in the generator. It is thereofor able to treat the air much faster than a PSA generator. More concretely, the air enclosed in this type of generator passes hrough the membrane following the hollow fibers. It discharges oxygen, water vapor and other gases that it contains, while nitrogen remains trapped in the membrane. This nitrogen is then collected at the outlet of the device.
Operating through a membrane or alternating pressurization, both types of generator allow the production of a pure nitrogen, ready to use. However, the PSA generator is better suited for applications requiring the highest levels of purity.