inert gas generator

It's a molecular seive. O₂ and other gases are filtered out from the air, leaving only high purity N₂ gas.

"Pressure Swing Adsorption"?

Possibly.

Are you aware that the Air has approx 70% nitrogen ? something if I remember correctly about 23% Oxygen and rest is others (CO₂ etc)

So you just take out the others and you are left with N₂

There are different ways to do it, the easiest way is to compress the air (liquify) and then go for selective vaporisation. Since the boiling points are different, you get almost pure gases correspondingly. But not the high purity ones.

Nitrogen is not inert, I know many refer to it being inert but it has vacancy on its outer electron shell allowing it to mix with other element gases, I jumped on this thread to get input on that subject I work in a weld shop where its always been debated.

Of course N₂ is not noble gas (in face any thing with ₂ will not be ). Nitrogen has 5 electrons in its outer orbit and it wants 3 more.

noble gases are He, Ne, Ar, Kr, Xe and Ra

Wiki

Because of the non-reactive properties of inert gases they are often useful to prevent undesirable chemical reactions from taking place. For example molecular nitrogen, a molecular inert gas, is often used in food packaging to ensure that food does not spoil in transit since no bacteria or fungi can flourish without the reactive gases oxygen or carbon dioxide, which the molecular nitrogen displaces, since most extant cells on Earth require the reactions which these gases are involved in to function. Most importantly since molecular nitrogen is inert it will not cause any reactions to take place in the food, possibly changing the intrinsic taste or smell, nor will it cause any chemical reactions in the human body. Thus the inert gas is used as a passive preservative, preventing biological decay, while being undetectable to the consumer since taste and olfactory senses require a chemical reaction to take place in order to send a signal to the brain. This is in contrast to active preservatives which react with the biological material of bacteria, fungi, and possibly the food itself changing the food's intrinsic taste or smell, or may even act directly on the consumer's taste and olfactory mechanisms.

In context of welding of course we mean noble gases when we say inert.

see a link of N2 as inert

http://dic.academic.ru/dic.nsf/enwiki/154952

In marine applications, inert gas refers to gases with a low content of oxygen that are used to fill void spaces in and around tanks for explosion protection. There are two types of inert gas which are either based on nitrogen or on flue gas.

In fact in transformers and a few electrical equipments, Heat exchanger purging etc the inert gas used is a high purity Nitrogen.