Technology

A Description of PSA Technology

Nitrogen P.S.A systems have been available for over 20 years. The technology is well established and well proven. There are typically two types of P.S.A systems; The dual & single Pressure Swing Systems.

The Dual PSA System
This system is made up of two beds of Carbon Molecular Sieve (CMS). Pre-treated compressed air
enters the bottom of the first “on-line” bed and passes across the CMS. Oxygen and other trace gases are preferentially adsorbed by the CMS allowing Nitrogen to pass through. After a pre-set time when the on-line bed is nearly saturated with adsorbed gases, the system automatically switches the bed to regenerative mode whilst the second, previously regenerated bed, comes on-line and takes over the separation process. The saturated bed is regenerated by rapidly reducing the pressure inside the CMS chamber so allowing the captured gases to escape to atmosphere. This continuous ‘swing’ in pressure between the adsorption and regeneration modes gives the technology its name.

The Single PSA System
The only difference between the dual PSA system and the single PSA system is that the single system only has one CMS chamber. The single system operates on a time served basis, Nitrogen production & regeneration. Unlike the dual system, when the CMS bed is in its regeneration state there is no Nitrogen production, pressure is maintained with the use of a small integral storage vessel.

Benefits : Nitrogen gas generators eliminate the need for costly, inconvenient high pressure gas cylinders in the work place. Including an integral oil free compressor isolated from the process, the generators deliver a continuous flow of Nitrogen gas without the need for secondary purification. ·

Improved Safety : Nitrogen is produced at low pressure’s thus removing the need for high pressure cylinders or liquid dewars.

Increased Efficiency : A constant, uninterrupted gas supply reduces downtime on bottle change-over and instrument calibration.

Simple Installation : Gas generators can be installed on or under a bench within close proximity of the instrument eliminating the need for long gas piping from cylinders located elsewhere.