Removal of Fine Particles from Flue Gas by Heterogeneous Condensation in WFGD System

摘要

A novel process is proposed to improve the removal of fine particles by heterogeneousrncondensation during limestone-gypsum desulfurization system from the flue gas. The supersaturationrnenvironment is achieved in the SO_2 absorption zone by means of flue gas humidification at the inlet ofrnWFGD system, which is achieved by spraying water evaporation at inlet of electrostatic precipitator (ESP)rnand installing a low-low temperature heat exchanger at WFGD inlet. The numerical calculation resultsrnindicate that the supersaturation vapor environment can be obtained in the SO_2 absorption zone during thisrnprocess. The fine particles in flue gas are activated in supersaturation vapor environment and act asrnnucleation centers to grow up to droplets, and the condensation grown droplets are then removed by therndesulfurization liquid and a high-efficiency demister. The influences of the relative humidity and temperaturernof WFGD inlet flue gas on the removal of fine particles are investigated in this paper. The results show thatrninlet flue gas with high relative humidity can promote the removal of fine particles, the performance of thernWFGD system for removal of fine particles can be significantly improved by this novel process, and thernremoval efficiency of WFGD system can be improved 40-50%.