关键词:

蒸汽相变, 超细颗粒, 洗涤塔, 脱除

Abstract:

Packed column scrubber in which vapor condensation with fine particles acting as nucleation nuclei was used to separate fine particles from combustion.The particle size distributions and concentrations before and after scrubbing were measured by the electrical low pressure impactor (ELPI).The microstructure and major element compositions of fine particles were analyzed by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) respectively.Based on this, the influences of operating parameters, such as the temperature difference between gas and water at the inlet of scrubber, the moisture contents of flue gas, liquid to gas rate, on the particle removal efficiency were investigated.The results showed that the morphology and compositions of the fine particles from coal and oil combustion were very different.The fine particles from coal combustion mainly were mineral substances of Si and Al, while the particles from oil combustion mainly were carbon.The removal efficiency of fine particles from coal combustion was higher than that of oil under the same conditions.It was also found that the removal efficiency increased with increasing inlet temperature difference between gas and liquid.When the temperature difference was the same, the condensational removal efficiency could be highly enhanced with increasing humidity of inlet gas. The influenceof liquid to gas ratio was related to the existence of heterogeneous condensation in the packed column scrubber.The result indicated that fine particles could be effectively removed by the packed column in which supersaturation of vapor and corresponding droplet growth by heterogeneous condensation were able to be achieved by adjusting the moisture contents of the inlet gas and the inlet temperature difference between flue gas and water.

Key words:

蒸汽相变, 超细颗粒, 洗涤塔, 脱除