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Volume 16, No. 7, July 2016, Pages 1757-1763 PDF(1000 KB)  
doi: 10.4209/aaqr.2015.11.0650   

Research into Haze Removal Method Based on Diffusion and Relative Motion

Lian-Ze Wang, Hong-Tao Niu, Ning-Ning Peng, Xiong Shen

Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China


  • Like Brownian diffusion of molecules, PM2.5 show intensive gradient diffusion.
  • Relative motion of device to polluted air has higher efficiency in large space.
  • The diffusion and relative motion could be used for haze removal.



A method for purifying polluted air in large open space was proposed and verified based on concentration gradient diffusion theory and relative motion principle of purifying device to polluted air. As to the sources of particle emitting, the purifying device works as a sink no matter it is moving or not. Both indoor and outdoor experiments have been made. In the indoor experiment, severe haze environment was simulated by fuming. The purifying device was made of metal wire and carbon cloth. The fixed device took 2.7, 6.2 and 13 minutes to reduce the particle concentration in the 7 m farthest corner of the laboratory to 50%, 20% and 0 respectively. By moving the device at 1 m s–1, the concentration could be reduced to 50% in merely 15 seconds. In outdoor experiment, 23.5% decrease of haze concentration was measured.



Keywords: Concentration gradient; Diffusion; Relative motion; Haze removal.



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