Process and device for cooling and rectifying gases in heat exchanger with a colder gas, particularly with (their) decomposition products

Claim 1

IN A PROCESS ALTERNATING IN TWO PERIODS, NAMELY A COOLING AND PURIFYING PERIOD AND A SCAVENGING AND COLDBLOWING PERIOD, IN WHICH COOLING AND PURIFYING PERIOD A CRUDE GAS MIXTURE IS PASSED THROUGH ONE OF TWO PERIODICALLY REVERSIBLE PASSAGEWAYS, OF A HEAT-EXCHANGER IN THE DIRECTION FROM THE WARM END TO THE COLD END THEREOF, WHEREBY SAID CRUDE GAS MIXTURE IS COOLED AND ITS GASEOUS IMPURITIES ARE FORZEN AND DEPOSITED IN SOLID STATE IN SAID ONE PASSAGEWAY OF SAID HEAT-EXCHANGER, BEFORE THE PURIFIED GAS MIXTURE IS SEPARATED INTO ITS COMPONENTS BY RECTIFICATION AT LOW TEMPERATURE, AND IN WHICH COLD-BLOWING AND SCAVENGING PERIOD A COLD GAS, PREFERABLY A COMPONENT OF SAID GAS MIXTURE, IS PASSED THROUGH THE OTHER OF SAID TWO PERIODICALLY REVERSIBLE PASSAGEWAYS OF SAID HEAT-EXCHANGER SAID OTHER PASSAGEWAY CONTAINING FROZEN GASEOUS IMPURITIES DEPOSITED DURING A PRECEDING COOLING AND PURIFYING PERIOD; IN THE DIRECTION FROM THE COLD END TO THE WARM END THEREOF, WHEREBY THE HEAT-EXCHANGER IS COOLED AND SAID DEPOSITED IMPURITIES ARE SCAVENGED AND DISCHARGED AT THE WARM END, THE IMPROVED METHOD FOR SCAVENGING SAID OTHER PASSAGEWAY DURING SAID COLD-BLOWING AND SCAVENGING PERIOD COMPRISING A FIRST PART OF SAID COLD-BLOWING AND SCAVENGING PERIOD IN WHICH THE COLD GAS IS PASSED THROUGH A SEPARATE PASSAGEWAY IN SAID HEAT-EXCHANGER IN THE OPPOSITE DIRECTION TO THAT OF THE CUDE GAS MIXTURE, WHEREBY SAID GAS IS WARMED, BEFORE IT IS PASSED THROUGH SAID IMPURITY-CONTAINING PASSAGEWAY TO BE SCAVENGED, AND A SECOND PART OF SAID COLD-BLOWING AND SCAVENGING PERIOD IN WHICH THE COLD GAS IS PASSED THROUGH SAID OTHER PASSAGEWAY, THEREBY COOLING SAID HEAT-EXCHANGER IN A KNOWN MANNER.