Liquefaction of gases

Claim 1

A METHOD OF COOLING A GAS TO A TEMPERATURE SUBSTANTIALLY BELOW 70*K. WHICH COMPRISES: (A) PASSING THE GAS TO BE COOLED, AT AN ELEVATED PRESSURE AND AT A TEMPERATURE BETWEEN ABOUT 65 AND 70* K., SERIALLY THROUGH A PLURALITY OF SEPARATE, FIRST COOLING ZONES; (B) SEPARATING A FEED STREAM OF COOLAND GAS, AT AN ELEVATED PRESSURE, INTO A PLURALITY OF SEPARATE STREAMS OF COOLANT GAS EQUAL IN NUMBER TO THE NUMBER OF SAID FIRST COOLING ZONES; (C) THEREAFTER, PASSING EACH OF SAID SEPARATE STREAMS OF COOLANT GAS THROUGH A PLURALITY OF EXPANSION TURBINES, EACH OF WHICH IS OPERATIVELY ASSOCIATED WITH ONE OF SAID PLURALITY OF FIRST COOLING ZONES, TO EXPAND EACH OF SAID SEPARATE STREAMS OF COOLANT GAS AND FORM AN EQUAL NUMBER OF SEPARATE STREAMS OF EXPANDED COOLANT GAS; (D) PASSING EACH OF SAID SEPARATE STREAMS OF EXPANDED COOLANT GAS THROUGH ONE OF SAID FRIST COOLING ZONES, IN INDIRECT HEAT EXCHANGE WITH SAID GAS TO BE COOLED AS SAID GAS TO BE COOLED PASSES THROUGH SAID FIRST COOLING ZONES, TO COOL SAID GAS TO BE COOLED IN EACH OF SAID FRIST COOLING ZONES TO A TEMPERATURE LOWER THAN THE TEMPERATURE OF SAID SEPARATE STREAMS OF COOLANT GAS PASSING TO SAID TURBINES AND PRODUCE AN EQUAL NUMBER OF SEPARATE STREAMS OF PARTIALLY HEATED, EXPANDED COOLANT GAS; (E) PASSING EACH OF THE SECOND AND SUBSEQUENT OF SAID PARTIALLY HEATED, EXPANDED STREAMS OF COOLANT GAS THROUGH A PLURALITY OF SECOND COOLING ZONES, SEPARATE FROM ONE ANOTHER AND FROM SAID FIRST COOLING ZONES, TO PRE-COOL THE ASSOCIATED ONE OF SAID SEPARATE STREAMS OF COOLANT GAS PASSING TO SAID TURBINES AND PRODUCE AN EQUAL NUMBER OF STREAMS OF ADDITIONALLY HEATED, EXPANDED COOLANT GAS; (F) RECOMBINING SAID PARTIALLY HEATED, EXPANDED COOLANT GAS FROM THE FIRST OF SAID COOLING ZONES AND SAID SEPARATE STREAMS OF ADDITIONALLY HEATED, EXPANDED COOLANT GAS FROM SAID SECOND COOLING ZONES, TO FORM A RETURN STREAM OF COOLANT GAS; (G) COOLING THE SAID FEED STREAM OF COOLANT GAS WITH SAID RETURN STREAM OF COOLANT GAS PRIOR TO THE SEPARATION OF SAID FEED STREAM OF COOLANT GAS INTO SAID PLURALITY OF SEPARATE STREAMS OF COOLANT GAS; AND (H) THEREAFTER, PASSING SAID RETURN STREAM OF COOLANT GAS TO A COMPRESSOR AND THENCE TO SAID FEED STREAM OF COOLANT GAS.

Claim 2

A METHOD OF COOLING A GAS TO A TEMPERATURE SUBSTANTIALLY BELOW 70*K. WHICH COMPRISES: (A) PASSING THE GAS TO BE COOLED, AT AN ELEVATED PRESSURE AND AT A TEMPERATURE BETWEEN ABOUT 65 AND 70* K., SERIALLY THROUGH A PLURALITY OF SEPARATE, FIRST COOLING ZONES; (B) SEPARATING A FEED STREAM OF COOLAND GAS, AT AN ELEVATED PRESSURE, INTO A PLURALITY OF SEPARATE STREAMS OF COOLANT GAS EQUAL IN NUMBER TO THE NUMBER OF SAID FIRST COOLING ZONES; (C) THEREAFTER, PASSING EACH OF SAID SEPARATE STREAMS OF COOLANT GAS THROUGH A PLURALITY OF EXPANSION TURBINES, EACH OF WHICH IS OPERATIVELY ASSOCIATED WITH ONE OF SAID PLURALITY OF FIRST COOLING ZONES, TO EXPAND EACH OF SAID SEPARATE STREAMS OF COOLANT GAS AND FORM AN EQUAL NUMBER OF SEPARATE STREAMS OF EXPANDED COOLANT GAS; (D) PASSING EACH OF SAID SEPARATE STREAMS OF EXPANDED COOLANT GAS THROUGH ONE OF SAID FRIST COOLING ZONES, IN INDIRECT HEAT EXCHANGE WITH SAID GAS TO BE COOLED AS SAID GAS TO BE COOLED PASSES THROUGH SAID FIRST COOLING ZONES, TO COOL SAID GAS TO BE COOLED IN EACH OF SAID FRIST COOLING ZONES TO A TEMPERATURE LOWER THAN THE TEMPERATURE OF SAID SEPARATE STREAMS OF COOLANT GAS PASSING TO SAID TURBINES AND PRODUCE AN EQUAL NUMBER OF SEPARATE STREAMS OF PARTIALLY HEATED, EXPANDED COOLANT GAS; (E) PASSING EACH OF THE SECOND AND SUBSEQUENT OF SAID PARTIALLY HEATED, EXPANDED STREAMS OF COOLANT GAS THROUGH A PLURALITY OF SECOND COOLING ZONES, SEPARATE FROM ONE ANOTHER AND FROM SAID FIRST COOLING ZONES, TO PRE-COOL THE ASSOCIATED ONE OF SAID SEPARATE STREAMS OF COOLANT GAS PASSING TO SAID TURBINES AND PRODUCE AN EQUAL NUMBER OF STREAMS OF ADDITIONALLY HEATED, EXPANDED COOLANT GAS; (F) RECOMBINING SAID PARTIALLY HEATED, EXPANDED COOLANT GAS FROM THE FIRST OF SAID COOLING ZONES AND SAID SEPARATE STREAMS OF ADDITIONALLY HEATED, EXPANDED COOLANT GAS FROM SAID SECOND COOLING ZONES, TO FORM A RETURN STREAM OF COOLANT GAS; (G) COOLING THE SAID FEED STREAM OF COOLANT GAS WITH SAID RETURN STREAM OF COOLANT GAS PRIOR TO THE SEPARATION OF SAID FEED STREAM OF COOLANT GAS INTO SAID PLURALITY OF SEPARATE STREAMS OF COOLANT GAS; AND (H) THEREAFTER, PASSING SAID RETURN STREAM OF COOLANT GAS TO A COMPRESSOR AND THENCE TO SAID FEED STREAM OF COOLANT GAS.