Patent ID: 8505333
Filing Date: 2013-08-13
Classification: F25J

Abstract:
1. A process for liquefying a natural gas stream, said process comprising: (a) introducing at least a portion of said natural gas stream into a first distillation column; (b) withdrawing a first predominantly liquid stream from said first distillation column via a first liquid outlet; (c) heating at least a portion of said first predominately liquid stream in a first heat exchanger to provide a first heated stream; (d) separating at least a portion of said first heated stream in a vapor-liquid separation vessel to provide a first heated vapor fraction and a first heated liquid fraction; (e) heating at least a portion of said first heated liquid fraction in a second heat exchanger, wherein the second heat exchanger is a kettle-type shell-and-tube heat exchanger comprising a shell and an internal weir extending from the bottom of said shell part way towards the top of said shell, wherein said shell defines an internal volume, wherein said internal weir divides the internal volume into a first side and a second side, wherein said heating of step (e) takes place on said first side of said internal weir; (f) withdrawing a second heated vapor fraction and a second heated liquid fraction from said second heat exchanger wherein said second heated liquid fraction is withdrawn from said second heat exchanger on said second side of said internal weir, wherein said second heated liquid fraction flows over an uppermost edge of said internal weir from said first side to said second side; (g) introducing at least a portion of said first and/or second heated vapor fractions into said first distillation column via a first vapor inlet, wherein said first vapor inlet is located at a vertical elevation below said first liquid outlet; and (h) introducing at least a portion of said second heated liquid fraction into said first distillation column via a first liquid inlet, wherein said first liquid inlet is located at a vertical elevation below said uppermost edge of said internal weir.