Method for cryogenic separation of air, and air separation plant

An air separation plant with a rectification column arrangement having a pressure column, a low-pressure column, and a raw argon column, wherein the air separation plant is configured,

• with direct or indirect use of a first proportion of an oxygen-enriched liquid from the pressure column, to form a first liquid pressure flow and to expand said first liquid pressure flow with production of a first flash gas while a first low-pressure liquid remains;
• to operate the raw argon column using a first head gas condensation arrangement and subject this head gas of the raw argon column to condensation with partial evaporation of a first cooling fluid provided using the first low-pressure liquid or a part thereof, wherein the first head gas condensation arrangement has a forced-flow condenser evaporator;
• and
• to feed a first evaporation gas, or a part thereof, formed during the partial evaporation of the first cooling liquid into the low-pressure column, and wherein:
• the gas line contains a first throttle valve;
• and
• the first throttle valve is designed to be adjusted by means of a control device in such a way that freezing of argon in the first head gas condensation arrangement is avoided, and in the process a pressure drop across the throttle valve of at least 50 mbar is at least temporarily generated.