Removal of particulate matter emitted from a subway tunnel using magnetic filters.
We removed particulate matter (PM) emitted from a subway tunnel using magnetic filters. A magnetic filter system was installed on the top of a ventilation opening. Magnetic field density was increased by increasing the number of permanent magnet layers to determine PM removal characteristics. Moreover, the fan's frequency was adjusted from 30 to 60 Hz to investigate the effect of wind velocity on PM removal efficiency. As a result, PM removal efficiency increased as the number of magnetic filters or fan frequency increased. We obtained maximum removal efficiency of PM10 (52%), PM2.5 (46%), and PM1 (38%) at a 60 Hz fan frequency using double magnetic filters. We also found that the stability of the PM removal efficiency by the double filter (RSD, 3.2-5.8%) was higher than that by a single filter (10.9-24.5%) at all fan operating conditions.
Exposure, Epidemiology, and Risk Program, Department of Environmental Health, Harvard School of Public Health , 401 Park Drive, Landmark Center West Room 417, Boston, Massachusetts 02115, United States.
Youn-Suk
YS
Son
Trieu-Vuong
TV
Dinh
Sang-Gwi
SG
Chung
Jai-Hyo
JH
Lee
Jo-Chun
JC
Kim
D000392:Air Movements; D000393:Air Pollutants / Q000737:chemistry*; D016902:Air Pollution, Indoor / Q000032:analysis; D005374:Filtration / Q000295:instrumentation*; D059346:Magnets; D052638:Particulate Matter / Q000737:chemistry*; D011890:Railroads; D014691:Ventilation / Q000295:instrumentation / Q000379:methods
D000393:Air Pollutants; D052638:Particulate Matter