The working principle of the external compression process is as follows: Air is pressurized by a compressor and enters an air separation unit. Low-pressure oxygen (about 0.12 MPa) is separated out through a distillation column, and then pressurized to the desired pressure by an external oxygen compressor. The compression process takes place outside the air separation unit, and the oxygen compressor operates independently of the main system, delivering compressed gas through pipelines.
The working principle of the internal compression process is as follows: after being pressurized by a compressor, air enters an air separation unit. The liquid oxygen separated out by the distillation column is directly pressurized to the target pressure by a liquid oxygen pump, and then vaporized through heat exchange with high-pressure air before being output. The compression process is integrated within the air separation unit, where a liquid oxygen pump and an air booster are used to replace the oxygen compressor, achieving an integrated process of "liquid compression-vaporization".
The external compression process is suitable for small and medium-sized air separation equipment, with low investment costs, making it ideal for enterprises with limited budgets. For industries with significant gas fluctuation, such as the metallurgical industry, the oxygen compressor offers flexible pressure regulation to adapt to changing demands. When the demand for liquid products is low and the proportion of liquid oxygen production is less than 8%, energy consumption is further reduced.
Internal compression process applicable scenarios, large-scale air separation equipment: production scale ≥ 3000m³/h, requiring high efficiency and large-scale production. High pressure demand, when the product pressure > 3.0MPa, the oxygen compressor cannot meet the demand, and internal compression is required. High demand for liquid products: when the proportion of liquid oxygen production > 8%, the energy consumption advantage is significant. High safety requirements, such as in the chemical and electronics industries, require reducing the risk of fire and explosion.
