Air separation units are equipment used for the separation and purification of gases or liquids. They are commonly used in chemical, petroleum, pharmaceutical and other industries. Air separation units usually consist of the following main equipment:

1. Separation Tower: The separation tower is the core equipment of the air separation unit, used to separate the components in the mixture. It is usually a tall tower-like structure with packing or plate structure inside, which achieves separation through the difference in physical or chemical properties of different components.

2. Compressor: The compressor is used to increase the pressure of the mixed gas so that it can enter the separation tower. Compressors usually use reciprocating or centrifugal compressors.

3. Expander: The expander is the opposite of the compressor and is used to reduce the gas pressure. In air separation units, expanders are often used to cool certain parts of the separation tower and recover energy.

4. Cooler: The cooler is used to reduce the temperature of the mixed gas to the required operating temperature of the separation tower.

5. Heating furnace (Heater): The heating furnace is used to increase the temperature of the mixed gas in order to achieve certain reactions or processes in the separation tower.

6. Adsorbent Bed: In some cases, the air separation unit may need to use an adsorbent bed for further purification. The adsorbent bed is used to adsorb impurity components in the mixed gas to make it purer.

In addition to the above equipment, the air separation equipment also includes auxiliary equipment such as various pipes, valves, control systems, and heat exchangers to ensure the smooth flow of fluids in the unit and to achieve operation and control. Specific equipment configurations and process designs vary based on different applications and requirements.