Improving the removal of fine particles in cyclone using heterogeneous vapor condensation enhanced by atomization

Abstract

Using a heat exchanger to cool high humidity flue gas can create a supersaturated water vapor environment, allowing fine particles to grow into large droplets by heterogeneous vapor condensation, which is conductive to the removal of fine particles by traditional equipment. However, due to the limited condensable vapor obtained by cooling, this technology can only be used in the flue gas with low particle concentration. In this study, atomization droplets were added before the heat exchanger to improve the effect of heterogeneous vapor condensation at high particle concentration, and then coupled with a cyclone separator, which was used for the deep treatment of the flue gas after the wet dedusting system. The particle removal characteristics were investigated through laboratory experiments and bypass experiments in a metallurgical company. The experimental results show that the application of atomization-heterogeneous condensation reduced the particles concentration after cyclone by 74.2 % compared with that of single heterogeneous condensation. Temperature-drop and atomized volume affected the removal of particles with size < 2 μm and > 2 μm, respectively. The industrial flue gas bypass experiment indicated that the system had strong adaptability to fluctuating conditions. When the inlet particle concentration did not exceed 2000 mg/Nm³, the outlet particle concentration can be maintained within 20 mg/Nm³.