Method of Removing Fe Particulate Matters from Subway Environments

Abstract

In subway environments, particulate matter is generated continuously by abrasion between wheels, rails and brake pads, and through contact between electric carlines and the pantograph. Particulate matter, 61-79% of which is composed of iron (Fe), is dispersed throughout subway stations, including platforms and waiting rooms, by train drafts. This study proposes a method for removal of Fe particulates from subway tunnels, which involves mounting magnetic dust collectors underneath operating subway trains. A mathematical model is developed to determine the size of dust collector needed and the minimum period required to remove all Fe particulate matter accumulated in subway tunnels. When the model was applied to Seoul Metropolitan Subway Line 7, which has an operational duration of 20 years, it was estimated that up to 3 years would be required to remove accumulated particulate matter if two collectors were mounted on all subway trains. After removal of accumulated particulate matter, the overall concentration of particulate matter in the tunnel was shown to decrease by 61.6% when dust collectors were mounted on 50% of subway trains.