Process and apparatus for air separation by rectification

An apparatus for separating air by rectification comprising:

• a first rectification column having a first rectification stage, a second rectification stage, feed means for introducing air to be separated, a first outlet means for removing nitrogen, a second outlet means for removing oxygen, and a third outlet means for removing an argon-enriched fraction, said third outlet means being in fluid communication with said second rectification stage;
• an argon column having a first conduit means, a second conduit means and a third conduit means, said first conduit means being in fluid communication with said third outlet means of said first rectification column to provide for delivery of an argon-enriched fraction from said first rectification column to said argon column, said second conduit means being in fluid communication with the bottom of said argon column and with said second rectification stage to provide for delivery of a bottom liquid from sai argon column to said second rectification stage, said third conduit means being positioned in the side of said argon column to provide for lateral removal of a fraction therefrom;
• a high-purity oxygen column in fluid communication with said third outlet means of said argon column;
• a high-purity nitrogen column, said high-purity nitrogen column being in heat exchange relation when the bottom of said high-purity oxygen column by means of a common condenser-evaporator, said high-purity nitrogen column comprising gas delivery means in fluid communication with said first rectification stage and liquid removal means in fluid communication with said first rectification stage;
• and
• a high-purity nitrogen removal pipe attached to said first rectification stage at a point several plates below the head of said first rectification stage.

An apparatus for separating air by rectification comprising:

• a first rectification column having a first rectification stage, a second rectification stage, feed means for introducing air to be separated, a first outlet means for removing nitrogen, a second outlet means for removing oxygen, and a third outlet means for removing an argon-enriched fraction, said third outlet means being in fluid communication with said second rectification stage;
• an argon column having a first conduit means, a second conduit means and a third conduit means, said first conduit means being in fluid communication with said third outlet means of said first rectification column to provide for delivery of an argon-enriched fraction from said first rectification column to said argon column, said second conduit means being in fluid communication with the bottom of said argon column and with said second rectification stage to provide for delivery of a bottom liquid from said argon column to said second rectification stage, said third conduit means being positioned in the side of said argon column to provide for lateral removal of a fraction therefrom;
• and
• a high-purity oxygen column in fluid communication with said third outlet means of said argon column.