LIQUEFIED NATURAL GAS PRODUCTION METHOD Russian patent published in 2005 - IPC

FIELD: equipment for gas liquefaction.

SUBSTANCE: method involves separating gas flow from gas pressure reducing plant inlet into two streams; feeding one stream to expansion turbine of expansion-and-compression apparatus; supplying another stream to compressor of above apparatus; directing cold gas from turbine outlet into tube space of one of two switchable freezing heat-exchangers and then to gas pressure reducing plant outlet. Pressurized gas from gas compressor outlet is also separated into two parts. The first part is fed in one of two switchable freezing heat-exchangers and then in recuperative heat-exchanger. Then the first part is divided into two streams. Each stream is expanded and one stream is fed to moisture collector means, another one is mixed with low-pressure gas exiting from moisture collector. The second part of compressed gas flow is directed from gas compressor outlet to vortex tube which generates low pressure hot gas for heating freezing heat-exchanger removed from operation and cold gas used for additional cooling of compressed gas flow moving through operative preliminary freezing heat exchanger.

EFFECT: increased efficiency.

1 dwg