Heterogeneous nucleation activation in a condensational scrubber for particulate abatement

Abstract

The effectiveness of a condensational growth technique for particle abatement, activated via heterogeneous nucleation, was evaluated both theoretically and experimentally. Based upon information present in the literature, the heterogeneous nucleation rate and particle activation probability were estimated as a function of the environmental conditions. This work demonstrated that it is possible to capture the dispersed particles in the water droplets with high efficiency, depending on operating conditions. Increased final particle size, which improves removal from the gas stream, was found with relatively high inlet vapor concentrations and low working temperatures. It is also worth noting that extreme working conditions might be useful for the particle coverage. In fact, both nucleation and growth processes are active at very low vapor concentrations, although the maximum growth factor at these conditions is relatively low. Although it is not valid in predicting the induction time, a theoretical evaluation of the activation probability provides an indication of the process effectiveness at high vapor concentrations and low inlet temperatures. In contrast, at low vapor concentrations, this method fails to predict the occurrence of the vapor condensation on particles. At the experimentally evaluated conditions, the characteristic induction and growth times are compatible with practical applications.