Removal of Pollution by Rain in a Shallow Air Flow

Abstract

A configuration with rain falling through a shallow flow of pollution-loaded air is examined theoretically. The pollution particles are made up of (NH4)2SO4 mixed with graphite. A numerical feedback technique is used for calculating the development of the droplets having the particles as nuclei, as they pass over a 300 m high ridge under steady exposure to removal by raindrops. The development of state parameters for air and vapor, together with droplet sizes, temperatures, equilibrium humidities, and rate of removal over the distributions are discussed. Dissipation of kinetic fall energy for droplets is shown to affect droplet behavior. Removal of pollution from low-level air by rain appears to be quite efficient.