Process of and apparatus for the production of argon

Claim 1

A PROCESS FOR THE PRODUCTION OF ARGON COMPRISING THE STEPS OF WITHDRAWING AN ARGON-RICH ARGON-OXYGENNITROGEN FRACTION AT A PREDETERMINED POINT OF A TWO-STAGE AIR RECTIFICATION PROCESS, THE OXYGEN AND NITROGEN CONTENT OF SAID FRACTION OF GASES BEING OF SUBSTANTIALLY EQUAL MAGNITUDE, RECTIFYING SAID ARGON-OXYGEN-NITROGEN FRACTION TO REMOVE THE NITROGEN SUBSTANTIALLY COMPLETELY THEREFROM, SEPARATING THE REMAINING ARGON-OXYGEN MIXTURE INTO SUBSTANTIALLY PURE OXYGEN AND SUBSTANTIALLY PURE ARGON BY THE APPLICATION OF COLD, PRE-COOLING COMPRESSED AIR AND CIRCULATING IT IN A CIRCUIT, EXPANDING THE PRE-COOLED COMPRESSED AIR IN ORDER TO PRODUCE THE REQUIRED COLD, INDIRECTLY COOLING A PORTION OF SAID ARGON-OXYGEN MIXTURE BY THE EXPANDED PRE-COOLED AIR, HEATING THE SEPARATED SUBSTANTIALLY PURE OXYGEN BY THE PRE-COOLED COMPRESSED AIR, WASHING OUT THE ARGON FROM SAID ARGON-OXYGEN-NITROGEN FRACTION BY MEANS OF THE EXPANDED PRE-COOLED AIR, AND DISCHARGING THE AIR RESULTING FROM THE WASHING OUT OF THE ARGON INTO THE ATMOSPHERE IN HEAT EXCHANGE WITH THE COMPRESSED AIR.