Calculated particle collection efficiencies of single droplets including inertial impaction, brownian diffusion, diffusiophoresis and thermophoresis

Abstract

Particle collection efficiencies of a single 100 μm dia. water droplet were calculated with a Runge-Kutta numerical solution for the particle equation of motion. The bulk gas properties were held constant at 65°C and 100 per cent r.h. whereas the water droplet temperature ranged from 10°C (water vapor condensing on the droplet) to 82°C (water evaporating from droplet). Potential flow was assumed for the gas flow profile around the droplet moving at its settling velocity of 30.0 cm s −1. The results show that over the 0.01–10μm particle dia. range, the calculated particle collection efficiency is significantly increased with colder water temperatures and decreased with warmer water temperatures. The calculated results for the case with both the water and gas temperature at 65°C (only inertial impaction and Brownian diffusion mechanisms) compares reasonably with previous reports.