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Messer - Air separation unit - ASU ( - Messer Group Anwendungstechnik


Air Separation Unit

Cryogenic Air Separation

ASU - top ( for mob ver)

Air separation units (ASU)

Air separation units (ASU)are designed for the production of: oxygen, nitrogen, argon in liquid or gaseous form from atmospheric air. Additionally, the ASU can produce rare gases - krypton, xenon, neon and helium.

Messer has 125 years of experience and numerous technologies necessary to design, build and operate a cost-effective gas supply system for our customers.

MESSER owns and operates more than 300 air separation plants for all types of applications in more than 40 countries.

Verschachtelte Anwendungen



Capacity: to 200 000 Nm3/h
Purity: to 99,9999%



Capacity: to 60 000 Nm3/h
Purity: to 99,999%



Capacity: up to 2,000 Nm3/h
Purity: up to 99.9999%

ASU - top 2 ( for mob ver) Duplicate 1

In order to best meet the requirements of our clients, Messer manufacturs each ASU according to the individual project, taking into account the specifics of the client’s production and the existing infrastructure. The installations are based on the most modern design solutions, are equipped with best-in-class components from renown suppliers and are characterized by a high level of automation, reliability and low specific energy consumption.

Working principle

Working principle

ASU 1. Compression of air – Ambient air is drawn in, filtered and compressed ... 2. Precooling of air – ... and precooled with chilled water. 3. Purification of air – Impurities such as water vapor and carbon dioxide are then removed from the air in a so-called molecular sieve. 4. Cooling of air – Because the gases which make up air only liquefy at very low temperatures, the purified air in the main heat exchanger is cooled to approx. -175°C. The cooling is achieved by means of internal heat exchange, in which the flows of cold gas generated during the process cool the compressed air. Rapid reduction of the pressure then causes the compressed air to cool further, whereby it undergoes partial liquefaction. Now the air is ready for the separating column, where the actual separation takes place. 5. Separation of air – Separation of air into pure oxygen and pure nitrogen is performed in two columns, the medium-pressure, and the low-pressure columns. The difference in boiling point of the constituents is exploited for the separation process. Oxygen becomes a liquid at -183°C and nitrogen at -196°C. The continuous evaporation and condensation brought about by the intense exchange of material and heat between the rising steam and the descending liquid produces pure nitrogen at the top of the low-pressure column and pure oxygen at the bottom. Argon is separated in additional columns and involves some extra steps in the process. 6. Withdrawal and storage – Gaseous oxygen and nitrogen are fed into pipelines for transport to users, e.g., steelworks. In liquid form, oxygen, nitrogen and argon are stored in tanks and transported to customers by road tankers

ASU plans

MESSER is...

We back world-class application know-how with our design, operations and maintenance experience plus a network of air separation units for back-up supply and to bolster reliability. In addition, we provide secure, consistent, customized and cost-effcient supply solutions supported by more than 125 years of industrial gases know-how. Our customers beneft from the experience of a large multinational company with the attention of a family-run business. Our people make the difference!

Teaser Fluid Catalytic Cracking Duplikat 2 Duplikat 4 Duplikat 1

Teaser Fluid Catalytic Cracking Duplikat 2 Duplikat 4



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