Numerical Calculations on Condensation/Coagulation of PbO and Fly Ashes in a Vertical-type Small Size Incinerator

Abstract

This study is about numerical calculations on condensation and coagulation of hazardous metallic species which are important physical phenomena in an incinerator. Lead oxide(PbO), one of major metallic species produced in the combustion process, is selected for the study. Governing equations are three moment forms of the General Dynamic Equation and a vapor balance equation made by adding the effect of condensation and coagulation to the well-known convective diffusion equation. These differential equations, expressed in dimensionless variables, are solved using the finite differenced method. Temperature and velocity fields considering the gravitational force, number concentration of metal vapors, and ash particle size distribution are selected as the factors influencing the result of total aerosol size distribution.