An air separation unit (ASU), fully known as an air separation equipment, is a device that utilizes air as the raw material to separate its components such as nitrogen, oxygen, and rare gases through physical methods. The ASU primarily operates through cryogenic separation, a technique that exploits the differences in physical properties of air at different temperatures to achieve separation. Its key technical components include the following:
1. Compressor: The feed air compressor is the core component of the air separation equipment, responsible for compressing air to the required pressure.
2. Pre-cooling and purification system: This includes an air pre-cooling system and a molecular sieve purification system, which are used to reduce the temperature of the air and remove impurities such as moisture and carbon dioxide.
3. Refrigeration system: It primarily utilizes an expansion mechanism for refrigeration, following the classic refrigeration cycle to achieve deep freezing of air.
4. Distillation system: Consisting of a low-pressure column, a medium-pressure column, and a condensation evaporator, it is the core of air separation equipment and an important device for achieving low-temperature separation.
5. Product delivery and storage system: including oxygen compressor, nitrogen compressor, storage tank, cryogenic liquid pump, vaporizer, etc., used to deliver the separated gas to users or store it for future use.
The core technology of air separation equipment involves multiple aspects, including working principles, technology types, key components, as well as technological innovation and localization. The continuous development and improvement of these technologies have provided efficient and reliable supplies of industrial gases such as oxygen and nitrogen for China's industrial sector, driving the rapid development of related industries.
