Method for cryogenic separation of air, and air separation system

An air separation plant with a main heat exchanger and a subcooling countercurrent heat exchanger and a rectification column system which comprises a high-pressure column, a second low-pressure column and an argon system (400), and which is configured such that

• the high-pressure column is operated under a first pressure,
• the low-pressure column is operated under a second pressure which is lower than the first pressure,
• the argon system comprises a crude argon column operated under a third pressure higher than 1.8 bar,
• gaseous or partially liquefied compressed air is cooled in the main heat exchanger and introduced into the high-pressure column,
• sump liquid (e) is taken from the first rectification column and introduced directly or indirectly into the low-pressure column,
• in the subcooling countercurrent heat exchanger
• at least one liquid stream (e, n1) from the high-pressure column is cooled in the subcooling countercurrent heat exchanger,
• at least one gaseous stream (n2) from the low-pressure column is heated in the subcooling countercurrent heat exchanger,
• an argon-enriched fluid (o) is taken from the low-pressure column and introduced into the argon system,
• a liquid argon product (v) is taken from the argon system and obtained as the final product,
• wherein
• the air separation plant is configured to introduce the liquid argon product (v) into the subcooling countercurrent heat exchanger and to cool it therein before it is discharged as the final product.