Method and apparatus for recovering argon from an air fractionating process

An apparatus for producing argon by the separation thereof from oxygen and nitrogen in a liquid air fractionation plant, characterized in that said apparatus comprises:

• a. an air fractionation column,
• b. a rectifying column having an inlet pipe connected to a middle point of said fractionation column of said fractionation plant for issuing a gaseous nitrogen, oxygen and argon containing product into the bottom of said rectifying column;
• c. a compressing and cooling circuit for the liquefaction of gaseous product coming out of the head zone of the rectifying column, the circuit including a throttling element for recycling the produced liquid into the head zone of the rectifying column;
• d. means interconnecting the head zone of the rectifying column and the cooling and compressing circuit such that the gaseous product at the top of the head zone is delivered to the circuit;
• e. a heat exchange disposed in the bottom of said rectifying column for transferring calories to the bottom zone of the rectifying column, the heat exchanger utilizing a fraction of the gaseous head zone product drawn through the circuit after the compression and before the cooling;
• f. means for delivering the compressed fraction to the heat exchanger disposed in the bottom of the rectifying column;
• g. a draining pipeline branching off from said bottom zone of said rectifying column, the pipeline draining the bottoms of the rectifying column, and
• h. a pipeline being interposed in said circuit between the cooling stage and the throttling element for supplying a fraction of the liquid product to the inlet of an argon-nitrogen separation column.