Process and apparatus for recovery of pure argon

A process for the recovery of pure argon comprising:

• separating air in a rectification system, said rectification system having at least one air separation column and a pure argon column;
• introducing an argon-enriched mixture of air gases into said pure argon column;
• withdrawing a substantially nitrogen-free argon product from the lower region of said pure argon column;
• and
• heating the lower region of said pure argon column by indirect heat exchange with a liquid heating medium.

An apparatus for separating air and recovering pure argon, said apparatus comprising:

• a rectification system, comprising at least one air separation column, a crude argon column and a pure argon column,
• a first conduit in fluid communication with said air separation column and said crude argon column for introducing fluid from said air separation column into said crude argon column,
• a second conduit in fluid communication with said crude argon column and said pure argon column for introducing fluid from said crude argon column into said pure argon column, and
• a heat exchanger in heat exchange relationship with the lower region of said pure argon column,
• wherein said heat exchanger is also connected to a liquid duct and said liquid duct is connected to a source of liquid heating medium.

An apparatus for separating air and recovering pure argon, said apparatus comprising:

• a rectification system comprising at least one air separation column, a crude argon column, and a pure argon column,
• a first feed duct connected to said crude argon column for introducing an argon-containing fraction,
• a second feed duct connected to said pure argon column for introducing an argon-enriched mixture of air gases,
• a first heat exchanger in fluid communication with the upper region of said crude argon column by a first vapor duct and by a first condensate duct,
• a second heat exchanger in fluid communication with the upper region of said crude argon column by a second vapor duct and a second condensate duct,
• a cooling medium duct connected to a source of cooling medium having an oxygen content of at least 10%, and
• expansion means positioned in said cooling medium duct,
• wherein said cooling medium duct, downstream of said expansion means, is in fluid communication with said first and second heat exchangers.

A process for recovery of pure argon comprising:

• separating air in rectification systems, said rectification system comprising at least one air separation column, a crude argon column, and a pure argon column;
• passing an argon-containing fraction into said crude argon column;
• recovering an oxygen-depleted argon stream from said crude argon column;
• introducing an argon-enriched mixture of air gases into said pure argon column;
• at least partly liquefying a head fraction from said pure argon column by indirect heat exchange with at least a portion of a cooling medium;
• and
• subjecting said oxygen-depleted argon stream to indirect heat exchange in a condenser-evaporator;
• wherein said portion of said cooling medium is fed into said condenser-evaporator after said indirect heat exchange with said head fraction of said pure argon column, and said cooling medium has an oxygen content of at least 10%.