Modeling and simulation of the processes of condensation dehumidifying of high humidity industrial exhaust gases were made.An allocation factor

α

was introduced in the model to quantitatively express the effect of condensation on dehumidification with two existing mechanisms of fogging and film condensation.The profiles of temperature and steam fraction as well as their gradients (the driving forces for heat and mass transfer) were obtained numerically for turbulent flow of exhaust gases in the annular space outside a cooling tube with constant wall temperature.Dehumidification by fogging was mainly controlled by the mechanism of steam supersaturation produced from the cross interaction of heat and mass transfer driven by the temperature and humidity gradients near the cooling wall. While a much rapid heat and mass transfer would be seen in the bulk flow field when film condensation took place.It could be concluded that the actual dehumidification process should reach an inter mediate status between fogging and film condensation.From the pilot experiment of DAP tail gas cooling and dehumidification in the region of 34%—57% reduction of steam fraction

the experimental results obtained were considerably consistent with the simulation results for the allocation factor α=0.2.