The membrane technology is used for nitrogen production in NGS-M generators. Their task is to separate nitrogen from other air components, the air mainly consists of 79% nitrogen, 21% oxygen and other gases, including argon in the amount of 0.9%.
NGS-M Nitrogen generators can be designed according to the individual requirements of the customer if it is a matter of the purity of obtained nitrogen, the destination (there is the possibility of generator container installation). This enables you to optimize investment costs and at the same time replace traditional methods of nitrogen delivery in the cylinders or in liquefied form.
In nitrogen generators NGS-M the membrane operation is constant, not requiring the regeneration process.
Compressed air is sent to the control system, and then to alternately located membrane modules (columns) filled with fiber (membranes), inside of which there is a thin layer separating the particles of gases constituting air.
The separation process is shown in the figure.
А – Compressed air inlet;
В – Oxygen-rich air outlet;
С – Nitrogen-rich air outlet;
D – Membrane layer;
Е – Support layer.
The separated nitrogen is sent to the outlet branch pipe of the membrane module, then passes through the collecting manifold to the measuring control system of nitrogen purity level. The air is enriched with oxygen and sent to the collecting manifold, and then beyond the premises.
To ensure maximum efficiency and safe operation of the membrane generator, and thus to extend the service life, it is necessary to provide the generator with a compressed air enrichment system. This system should include coalescing filters, that provide the maximum allowable amount of oil in the compressed air at the level of 0.01 mg/m3 (the recommended amount is 0.003 mg/m3, which the system can provide: filter with coalescing insert and filter with carbon insert). Permissible solid particle content is 0.01µm. Before entering the generator, a coal module should be installed to separate compressed air from hydrocarbon vapours and ozone, which adversely affect the operation of the membrane modules. In addition, the dew point temperature of the compressed air should be maintained at the level of -40°C, and even -70°С.
Technical data of membrane nitrogen generators and the requirements for compressed air:
|Nitrogen generator series:||NGS-M|
|Operating pressure||6 – 13 bars|
|Compressed air temperature||max. 45°C|
|The content of solid particles in compressed air||< 0,01 µm|
|The content of oil in compressed air||0,003 mg/m3|
|The recommended temperature in the dew point of compressed air||– 40, – 70°C,|
|Ambient medium temperature||From +5 to +50°C|
|The obtained amount of nitrogen||Up to 500 m3/h|
|The content of solid particles in nitrogen||< 0,01 µm|
|Nitrogen purity||Up to 99,5 %|