Process of and apparatus for separating gases with cold production by workproducing expansion of low-boiling product

Claim 1

IN A PROCESS FOR THE SEPARATION OF A GAS MIXTURE BY LIFQUEFACTION AND RECTIFICATION AT RELATIVELY LOW TEMPERATURES, USING A RECTIFYING COLUMN ARRANGEMENT WITH AT LEAST THREE STAGES 1-3 AND REVERSING HEAT EXCHANGING MEANS 4-8 FOR COOLING SAID GAS MIXTURE BY HEAT EXCHANGE WITH SEPARATION PRODUCTS; THE METHOD WHICH COMPRISES SEPARATING THE GAS MIXTURE IN A PRELIMINARY FIRST RECTIFICATION STAGE 1 AT A GAS PRESSURE ABOVE THE PRESSURE CUSTOMERY IN A TWO STAGE PROCESS, PARTICULARLY BETWEEN 9 AND 12 ATMOSPHERES ABSOLUTE, INTO A SUBSTNATIALLY PURE FRACTION OF THE LOWER BOILING COMPONENT N2 AND A LIQUID FRACTION ENRICHED WITH THE HIGHER BOILING COMPONENT 02, WITHDRAWING AT LEAST PART OF SAID LOWER BOILING COMPONENT N2 IN GASEOUS FROM, WARMING IT BY HEAT EXCHANGING MEANS 6 WITH AT LEAST PART OF ITSELF IN A WARM STATE; EXPANDING SAID LOWER BOILING COMPONENT 14 WITH THE PRODUCTION OF EXTERNAL WORK, PASSING SAID LOWER BOILING COMPONENT AT LEAST PARTLY THROUGH SAID REVERSING HEAT EXCHANGING MEANS 6 TO PUT THE LOWER BOILING COMPONENT N2 IN SAID WARM STATE, USING AT LEAST A PART OF THE LOWER BOILING COMPONENT N2 TO WARM ITSELF BY HEAT EXCHANGE IN COUNTERFLOW BEFORE SAID EXPANSION WITH THE PRODUCTION OF EXTERNAL WORK 15 AND THEREAFTER PASSING IT THROUGH SAID REVERSING HEAT EXCHANGING MEANS 5 TRANSFERING THEREBY COLD TO THE SEPARATION PROCESS, WITHDRAWING SAID LIQUID FRACTION ENRICHED WITH THE HIGHER BOILING COMPONENT O2 FROM SAID PRELIMINARY FIRST RECTIFICATION STAGE 1, PASSING IT INTO A MEDIUM SECTION OF A SECOND RECTIFICATION STAGE 2, SEPARATING IT THEREIN INTO A SUBSTANTIALLY PURE FRACTION OF THE LOWER BOILING COMPONENT N2 AND A LIQUID FRACTION ENRICHED WITH THE HIGHER BOILING COMPONENT 02, WITHDRAWING 19, 20 AT LEAST PART OF SAID LOWER BOILING FRACTION N2 IN LIQUID FORM AS A WASHING LIQUID AND PASSING IT INTO THE HEAD OF A THIRD STAGE 3, WITHDRAWING SAID LIQUID FRACTION ENRICHED WITH THE HIGHER BOILING COMPONENT O2 FROM THE LOWER END OF THE SECOND STAGE AND PASSING IT INTO A MEDIUM SECTION OF THE THIRD STAGE 3, SEPARATING IT THEREIN INTO A SUBSTANTIALLY PURE FRACTION OF LOWER BOILING COMPONENT N2 AND A SUBSTANTIALLY PURE FRACTION OF HIGHER BOILING COMPONENT O2, WITHDRAWING THE LOWER BOILING COMPONENT N2 AND AT LEAST PART OF THE HIGHER BOILING COMPONENT O2 IN GASEOUS FORM AND PASSING THEM THROUGH SAID REVERSING HEAT EXCHANGING MEANS 5, 8, AND WITHDRAWING 22 PART OF THE HIGHER BOILING COMPONENT O2 AS A LIQUID.