Numerical simulation on the growth of polydisperse fine SiO2 particles by water vapor condensation.

The three-stage model was utilized to analyze the law of grown particle size distribution for amplification of polydisperse SiO 2 particles in actual water vapor environment. The predicted results demonstrate that the dispersity is narrowed compared with experimental data and the difference between them is large at higher level of supersaturation. Moreover, representative affecting factors on particle growth are discussed. Specifically, the increase of particle number concentration is the significantly negative effect on the particle growth. It leads to the failure of nucleation of small size particles and condensation on large size particles resulting in the several times reduction of arithmetic mean droplet size. Additionally, the improvement of the peak of initial particle size and inlet gas flow temperature on the condition of heating gas flow is not beneficial to particle growth. Besides, the reduction of surface tension of liquid phase can improve the growth strongly at lower level of supersaturation. [Display omitted] • The three-stage model was utilized to analyze the law of grown PSD by water vapor. • The actural water vapor environment of growth tube is described in the model. • The dispersity of PSD by simulation and experiment were evaluated contrastively. • The characteristics of particle growth on typical affecting factors are discussed. [ABSTRACT FROM AUTHOR]