Removing impurities from a gas liquefaction system with aid of extraneous gas stream

Claim 1

THE METHOD OF SEPARATING A GASEOUS MIXTURE INTO OUTPUT PRODUCTS BY LIQUEFRACTION AND FRACTIONATION WHICH COMPRISES, COOLING A MAJOR PART OF THE GASEOUS MIXTURE IN A COMPRESSED CONDITION BY THE REFRIGERATING EFFECT OBTAINED BY COUNTERCURRENT HEAT EXCHANGE IN A REVERSING HEAT EXCHANGE ZONE WITH COLD OUTPUT PRODUCT MATERIAL OF THE SEPARATION TO ELIMINATE IMPURITIES THEREFROM, FURTHER COOLING THE PURIFIED MIXTURE TO PRODUCE VAPOROUS AND LIQUEFIED FRACTIONS, WARMING A VAPOROUS FRACTION OF THE FURTHER COOLED GASEOUS MIXTURE BY COUNTERCURRENT HEAT EXCHANGE RELATION WITH A MINOR PART OF THE GASEOUS MIXTURE IN A COMPRESSED CONDITION, THEN COMBINING THE MINOR PART OF THE GASEOUS MIXTURE WITH THE MAJOR PART THEREOF ABOUT TO BE SUBJECTED TO SAID FURTHER COOLING, EXPANDING THE WARMED VAPOROUS FRACTION OF THE PURIFIED FURTHE COOLED GASEOUS MIXTURE, AND THEN FRACTIONATING THE EXPANDED VAPOROUS FRACTION WITH A LIQUID FRACTION OF THE FURTHER COOLED GASEOUS MIXTURE TO PROVIDE THE COLD OUTPUT PRODUCTS OF THE SEPARATION.