Large Capacity Air Separation Unit

NEWTEK's Large Capacity ASU operates based on the core principle of cryogenic rectification, leveraging the boiling point differences of air components (oxygen: 90.18 K, nitrogen: 77.36 K, argon: 87.3 K) to achieve precise separation. The working process is divided into four key stages:
 

Air Filtration & Compression:
Atmospheric air is first filtered to remove dust and mechanical impurities, then compressed to 0.6-1.3 MPa by high-efficiency centrifugal compressors to prepare for subsequent cooling.

Pre-Cooling & Purification:

Compressed air enters an air cooling column to be cooled by chilled water, then passes through dual adsorbers (alternately working and regenerating) to eliminate moisture, carbon dioxide, and hydrocarbons-preventing pipeline blockages or equipment damage caused by freezing.

Cryogenic Liquefaction:

Purified air flows into the main heat exchanger, where it is cooled to near-liquid temperature by countercurrent heat exchange with low-temperature product gases (nitrogen, oxygen). A portion of the cooled air expands and cools further via a turbo-expander (generating the low temperature required for liquefaction), while the rest is directly liquefied.

Rectification Separation:

Liquefied air enters the lower rectification column, where rising gas and descending liquid undergo repeated heat and mass exchange-nitrogen (low boiling point) enriches in the vapor phase and rises to the top, while oxygen (high boiling point) concentrates in the liquid phase and sinks to the bottom. The separated nitrogen is condensed into liquid nitrogen in the main condenser, and part of it is refluxed to the upper rectification column for secondary purification. Oxygen-enriched liquid from the lower column is sent to the upper column for further rectification, producing high-purity oxygen, nitrogen, argon, and rare gases. Finally, the products are either supplied as gas or condensed into liquid for storage.