Removal of DPM from an air stream using micron-scale droplets

Abstract

Respiratory exposures to diesel particulate matter (DPM) present health risks, particularly in confined environments with a relatively high number of emission sources. Despite a variety of existing control technologies, exposures in some occupational environments remain unacceptably high (e.g., underground mine environments), and new technologies and abatement strategies are needed. The physics of droplet-particle interactions suggests that micron-scale water drops can effectively scavenge DPM from an air stream. Here, experimental results are presented on DPM removal from a diesel exhaust stream using a fog of water droplets. Measured scavenging coefficients, based on both number density and mass, show that significant DPM removal is possible. The potential scavenging mechanisms at play are discussed, and insights are offered on future work necessary for scale-up of a fog-based exhaust treatment technology.