Method and apparatus for liquefaction of natural gas

Claim 1

THE METHOD OF LIQUEFYING A GAS COMPRISING THE STEPS OF SUPPLYING THE GAS IN A PROCESS STREAM AT AN ELEVATED TEMPERATURE AND PRESSURE, REMOVING HEAT FROM THE GAS TO REFRIGERATE THE GAS TO A TEMPERATURE AT WHICH IT IS CONDENSED TO A LIQUEFIED STATE AT THE PRESSURE CONDITIONS EXISTING, EXPANDING THE LIQUEFIED GAS TO LOWER PRESSURES FOR STORAGE AND TRANSPORTATION WHEREBY A PORTION OF THE COLD LIQUEFIED GAS IS FLASHED OFF UPON EXPANSION WITH FURTHER REDUCTION IN TEMPERATURE, SEPARATING THE FLASHED VAPORS FROM THE LIQUID, REMOVING MOISTURE FROM THE PROCESS STREAM TO REDUCE THE MOISTURE CONTENT TO A LEVEL BELOW THE DEW POINT AT TEMPERATURE CONDITIONS EXISTING DURING THE PROCESS TO PREVENT THE FORMATION OF FROZEN SOLIDS, AND IN WHICH THE REFRIGERATION SYSTEM FOR HEAT EXCHANGE TO REMOVE HEAT FROM THE PROCESS STREAM COMPRISES A SUBSTANTIALLY CLOSED SYSTEM EMBODYING A COMPRESSION AND EXPANSION CYCLE WHEREIN THE EXPANSION IS SUBDIVIDED INTO A HIGH PRESSURE SEGMENT AND A LOW PRESSURE SEGMENT WITH THE REFRIGERANT FROM THE HIGH PRESSURE SEGMENT FLOWING TO THE LOWER PRESSURE SEGMENT FOR FURTHER EXPANSION AND COOLING AND WHEREIN THE PROCESS STREAM PASSES IN HEAT EXCHANE RELATION WITH THE REFRIGERANT FIRST WITH THE HIGH PRESSURE SEGMENT AND THEN WITH THE LOW PRESSURE SEGMENT.

Claim 2

THE METHOD OF LIQUEFYING A GAS COMPRISING THE STEPS OF SUPPLYING THE GAS IN A PROCESS STREAM AT AN ELEVATED TEMPERATURE AND PRESSURE, REMOVING HEAT FROM THE GAS TO REFRIGERATE THE GAS TO A TEMPERATURE AT WHICH IT IS CONDENSED TO A LIQUEFIED STATE AT THE PRESSURE CONDITIONS EXISTING, EXPANDING THE LIQUEFIED GAS TO LOWER PRESSURES FOR STORAGE AND TRANSPORTATION WHEREBY A PORTION OF THE COLD LIQUEFIED GAS IS FLASHED OFF UPON EXPANSION WITH FURTHER REDUCTION IN TEMPERATURE, SEPARATING THE FLASHED VAPORS FROM THE LIQUID, REMOVING MOISTURE FROM THE PROCESS STREAM TO REDUCE THE MOISTURE CONTENT TO A LEVEL BELOW THE DEW POINT AT TEMPERATURE CONDITIONS EXISTING DURING THE PROCESS TO PREVENT THE FORMATION OF FROZEN SOLIDS, AND IN WHICH THE REFRIGERATION SYSTEM FOR HEAT EXCHANGE TO REMOVE HEAT FROM THE PROCESS STREAM COMPRISES A SUBSTANTIALLY CLOSED SYSTEM EMBODYING A COMPRESSION AND EXPANSION CYCLE WHEREIN THE EXPANSION IS SUBDIVIDED INTO A HIGH PRESSURE SEGMENT AND A LOW PRESSURE SEGMENT WITH THE REFRIGERANT FROM THE HIGH PRESSURE SEGMENT FLOWING TO THE LOWER PRESSURE SEGMENT FOR FURTHER EXPANSION AND COOLING AND WHEREIN THE PROCESS STREAM PASSES IN HEAT EXCHANE RELATION WITH THE REFRIGERANT FIRST WITH THE HIGH PRESSURE SEGMENT AND THEN WITH THE LOW PRESSURE SEGMENT.