Falling film evaporation

which is one efficient technology of heat and mass transfer

has been used in air separation field. The principles and characteristics of the main downflow condenser/reboiler in air separation are analyzed

the dynamic characteristics of falling film are illustrated from the aspects of the wave characteristics and breakdown characteristics

the influence of inlet flow rate

wall structure

components of working medium and heat flux density on the heat and mass transfer are reviewed in this paper. The occurrence regularity of critical heat flux and the dynamic characteristics of the superheated surface rewetting with liquid film for the progress of falling film of cryogenic liquid nitrogen in the large space plate are emphasized，some available heat transfer correlations for the progress of falling film evaporation in the vertical channels are concluded. Due to the speciality of physical property and channel structure

there is a significant gap applying the existing heat transfer correlations of working medium with normal temperature to the main downflow condenser/reboiler in air separation field. At last

it is pointed out that the further study of falling film evaporation of cryogenic fluid in the complex narrow channel under the small heat transfer temperature difference is needed.