Column for separating air by cryogenic distillation, air separation device comprising such a column and method for producing such a column

A method for producing a lower pressure column of an air separating device that can be used for production with and without argon, wherein the lower pressure column is thermally connected with a higher pressure column, wherein the lower pressure column comprises:

• a main outer shell;
• a lower distillation segment, a first intermediate distillation segment disposed above the lower distillation segment, a second intermediate distillation segment disposed above the first intermediate distillation segment, a third intermediate distillation segment disposed above the second intermediate distillation segment, and an upper distillation segment disposed above the third intermediate distillation segment, wherein the first intermediate distillation segment is surrounded by an auxiliary shell, wherein the auxiliary shell has a radius that is smaller than the radius of the main outer shell, thereby forming an annular space between the auxiliary shell and the main outer shell;
• an annular sealing member sealingly joining the auxiliary shell with the main outer shell, wherein the annular space comprises an upper section and a lower section;
• a first liquid inlet disposed on the main outer shell between the first intermediate distillation segment and the second intermediate distillation segment;
• a second liquid inlet disposed on the main outer shell between the second intermediate distillation segment and the third intermediate distillation segment;
• a third liquid inlet disposed on the main outer shell above the third intermediate distillation segment and below the upper distillation segment;
• a lower liquid inlet disposed on the main outer shell below the annular sealing member;
• an upper gas inlet disposed on the main outer shell above the annular sealing member;
• wherein the method comprises the step of:
• determining whether the lower pressure column will be used in the production of argon;
• and
• (A) if the lower pressure column will be used for the production of argon, the method further comprises the steps of:
• configuring the first intermediate distillation segment to have the same capacity as the second intermediate distillation segment,
• blocking the first liquid inlet,
• configuring the second liquid inlet to receive an oxygen-rich liquid from a bottom section of the higher pressure column,
• configuring the third liquid inlet to receive a liquid air stream,
• configuring the lower liquid inlet to receive a liquid from an argon column and introduce said liquid into the lower section of the annular space,
• configuring the upper gas inlet to receive a vaporized liquid from the argon column and introduce said vaporized liquid into the upper section of the annular space;
• (B) if the lower pressure column will be used without the production of argon, the method further comprises the steps of:
• configuring the first intermediate distillation section to have a higher capacity than the second intermediate distillation segment,
• blocking the lower liquid inlet,
• blocking the upper gas inlet,
• blocking the third liquid inlet,
• configuring the first liquid inlet to receive an oxygen-rich liquid from the bottom section of the higher pressure column, and
• configuring the second liquid inlet to receive the liquid air stream.