Process of and apparatus for lowtemperature separation of air

Claim 1

IN A PROCESS FOR THE LOW-TEMPERATURE SEPARATION OF AIR BY RECTIFICATION IN WHICH AIR FREED OF MOISTURE AND CARBON DIOXIDE IS AT LEAST PARTLY LIQUEFIED AND THE GASEOUS AND LIQUEFIED PORTIONS ARE RECTIFIED TO SEPARATE OXYGEN AND NITROGEN PRODUCTS, WHICH PRODUCTS ARE USED TO COOL FURTHER PORTIONS OF AIR, SUPPLYING THE ENTIRE LOWTEMPERATURE REFIGERATION RREQUIREMENT FOR SUCH PROCESS WHICH EXCEEDS THAT REGAINED FROM THE WARMING OF SAID OXYGEN AND NITROGEN RICH PRODUCTS DURING AT LEAST A SUBSTANTIAL PERIOD OF CONTINUOUS OPERATION BY PROVIDING A BODY OF LIQUID HAVING A COMPOSITION SIMILAR TO ONE OF THE LIQUIDS INVOLVED IN THE AIR SEPARATION PROCESS; HOLDING SUCH BODY OF LIQUID AT LOW TEMPERATURE AND SEPARATE FROM THE LIQUIDS PRESENT IN THE SEPARATION PROCESS; AND, DURING SAID PERIOD OF CONTINUOUS OPERATION, CONTINUOUSLY FEEDING PORTIONS OF SAID BODY OF LIQUID TO THE RECTIFICATION WHERE THE LIQUID COMPOSITION IS SIMILAR TO THAT OF THE BODY OF LIQUID, AND AT A RATE SUFFICIENT TO SUPPLY SAID ENTIRE LOW-TEMPERATURE REFRIGERATION REQUIREMENT, THE GAS PRODUCTS RESULTING FROM THE LIQUID FED TO THE RECTIFICATION FROM SAID BODY SUPPLEMENTING SAID OXYGEN AND NITROGEN RICH PRODUCTS IN COOLING THE FURTHER PORTIONS OF AIR.