OPTIMUM FIN DESIGNS FOR DOWNFLOW REBOILERS

摘要

A plate-fin heat exchanger or downflow reboiler/condenser which uses optimum fin dimensions to increase the efficiency of heat transfer between evaporating and condensing fluids such as cryogens (e,g., oxygen and nitrogen) is disclosed together with a cryogenic air separation unit having such a reboiler/condenser. In one embodiment, the plate-fin heat exchanger has a plurality of fins disposed between neighborin g parting sheets of uniform fin height less than or equal to 0.20 inch, fin frequency greater than or equal to 25 in-1 and fin thickness less than or equal to 0.008 inch. Such optimum fin s are most effectively employed at least within the first heat transfer section downstream of the hardway distributor section of the evaporating stream passages and within the entire heat transfer section between the inlet and outlet distributor sections of the condensing stream passages.