Vapor Condensation for Particulate Abatement

The reduction of particulate emission is among the most challenging problems in research field of pollutant control in combustion systems. This is due to very low efficiency of conventional separators, such as electrostatic precipitator, cyclone wet scrubber, in the collection of submicronic particles. To increase the diameter of fine and ultrafine particles by means of condensation of water vapor on the particles themselves seems to be a promising technique for industrial applications [1, 2]. Although several data are present in literature in the field of meteorology, cloud physics and aerosol science on nucleation and growth of droplets on foreign nuclei, a systematic analysis on dependence of such a process on parameters relevant from industrial point of view is not yet available. As a matter of a fact, temperature, partial pressure, properties of solid nuclei strongly affect the characteristic time and the efficiency of heterogeneous nucleation and the related dependence are needed for a proper design of a real abatement device. The aim of this work is to summarize the main physical relations governing the nucleation process and to describe the criteria followed in the design and set up of an experimental apparatus realized for the study of heterogeneous nucleation on submicronic particles in different conditions.