Process for removing solid carbon dioxide from air during its rectification

Claim 1

A PROCESS FOR REMOVING SOLID CARBON DIOXIDE FROM GASEOUS AIR DURING THE FRACTIONATION THEROF BY COMPRESSION AND COOLING, WHICH COMPRISES PROVIDING A FIRST STREAM AND A SECOND STREAM OF SAID GASEOUS AIR FROM A SOURCE OF AIR UNDER PRESSURE; EXPANDING SAID FIRST STREAM WITH PRODUCTION OF EXTERNAL WORK, WHEREBY CARBON DIOXIDE CONDENSES AND IS ENTRAINED BY THE GAS AS SNOW; LIQUEFYING PART OF SAID SECOND STREAM OF GASEOUS AIR BY COOLING AND THROTTLING, CARBON DIXOIDE BEING PRECIPITATED IN THIS LIQUID AS SNOW; WASHING AND RECTIFYING SAID GASEOUS FIRST STREAM WITH A MIXTURE OF THE LIQUEFIED PART OF THE SECOND STREAM AND LIQUID OBTAINED BY RECTIFYING THE GASEOUS FIRST STREAM AND THE GASEOUS PART OF THE SECOND STREAM IN THE HIGH PRESSURE COLUMN OF A TWO-STAGE RECTIFIER; THUS SUSPENDING ALL THE CARBON DIOXIDE IN THE LIQUID MIXTURE; SIMULTANEOUSLY RECTIFYING THE GASEOUS PART OF SAID SECOND STREAM WITH THE LIQUID OBTAINED BY RECTIFICATION IN THE HIGH PRESSURE COLUMN; CLEANING SAID LIQUID MIXTURE BY FILTRATION AND ADSORPTION; AND LEADING IT INTO THE LOW-PRESSURE STAGE OF THE TWO-STAGE RECTIFIER.