Ask the Experts: Why choose a Nitrogen Generator for your application?

Nitrogen generators are a more cost-effective option than liquid nitrogen filled cylinders, and are easier to manage and maintain; they are the preferred choice for most businesses who use nitrogen within their processing and packing divisions. We take a look at how nitrogen generators work and why nitrogen generator installation is such a popular option.

What are nitrogen generators?

A nitrogen generator is a device that produces 90%+ pure nitrogen gas from the atmosphere, which naturally contains only 78% nitrogen. There are two variants of nitrogen generators, and both nitrogen generator designs work by filtering atmosphere to separate the nitrogen from the other elements.

Membrane nitrogen generators

A membrane nitrogen generator works by compressing atmospheric air and passing it through a hollow fibre membrane, filtering out parts of air (primarily oxygen) leaving behind a high purity nitrogen gas.

Pressure Swing Absorption nitrogen generator

A pressure swing absorption (PSA) nitrogen generator design is similar to that of a membrane nitrogen generator. The basis of the operation is still compressing atmospheric air, however, instead of passing through a membrane a PSA generator will pass the air through carbon molecular sieves. This sieve only allows the smaller nitrogen molecules to pass through whilst all the larger molecules are absorbed. The resultant gas is high purity nitrogen. A PSA generator relies on at least two of these sieves and a pressure differential between them.

What applications use nitrogen generators?

Pure nitrogen is used in a whole range of industries including food processing, chemical plants, pharmaceuticals, aerospace and electronics. Some of the types of applications where you would find a nitrogen generator are:

• Aircraft tyres: nitrogen is drier than standard compressed air, which often contains water molecules as a result of the process of condensing. Because a nitrogen tank is dry, once the tyres are filled, the pressure remains more stable during heating and cooling phases experienced by the aircraft. Additionally, because a nitrogen molecule is slightly larger than an oxygen molecule, it is less likely to permeate the tyre.
• Chemical and petrochemical environments: nitrogen is an inert gas, making it a safer option for maintaining safety standards in an industrial setting during the cleaning of process vessels. Nitrogen generators are often also used for pressure testing of pipelines, the transportation of chemical agents and the regeneration of catalysts.
• Electronics: nitrogen generators are used in the heat treatment of finished products as well as blowing and cleaning. They are also used widely in soldering processes, and nitrogen is the key component in displacing oxygen during the production of semi-conductors and electrical circuits.
• Fire protection: nitrogen generators are used in fire sprinkler systems in place of air for dry pipe and pre-action because nitrogen prevents corrosion. Nitrogen generator installation is also used in hypoxic air fire prevention systems, whereby the production of air with very low oxygen content is used to prevent a fire.
• Oil & gas industries: because of its inert nature, nitrogen is used to prevent explosions and fire risks, as well as in the transportation or transfer of hydrocarbons. Nitrogen generator designs also enable them to be used in pipeline testing and purging, as well as in hydrocarbon storage facilities.

Why is a nitrogen generator installation preferable to gas cylinders?

Where nitrogen is used in volume, nitrogen cylinders are likely to be consumed rapidly, creating the need for manual switches of new cylinders and repeated deliveries or storage of spare bottles for stock. This can be a problem, particularly where nitrogen is critical or is used as risk prevention and in safety applications. Additionally, nitrogen generator installation prevents the need for the manual handling of cylinders. Finally, the price of nitrogen fluctuates, leading to variable overhead costs and the inability to forecast.

In all, nitrogen generators ultimately provide a more convenient, reliable and cost-effective option than cylinders. Glaston’s engineers are experts in nitrogen generator design and can advise you on the most appropriate option for your business. We also offer nitrogen generator installation, making the process of choosing and implementing a nitrogen generator stress-free, as well as nitrogen generator maintenance.