Theoretical Analysis of Acid Dew Point Temperature and Vapour Condensation Characteristics of the Flue Gas

Abstract Based on the gas-liquid phase equilibrium and multi-component diffusion theory, an analytical model for predicting acid dew point temperature and vapour condensation characteristics of flue gas was developed. The effects of components content, ash particle radius, wall temperature, coal-burned type and excess air ratio have been investigated. The results indicated that the acid dew point temperature and vapour condensation rate will increase with both water and sulfuric acid vapour contents increase. Vapours are not prone to condense on the ash particles when the particle radius is less than the corresponding critical condensing radius. The vapour condensation characteristics can be divided into two different stages with the wall temperature varies. The particle radius has a significant influence on the vapour condensation characteristics in the higher temperature stage. The acid dew point temperatures present significant differences for different coal-burned types, and the water vapour condensation rate is more sensitive to excess air ratio compared with the acid condensation rate.