Study On Transport Mechanisms Of Fine Particles From Indoor Combustion Sources

Indoor air pollution has been a focusing environment issue currently, not only because individuals are encountered serious exposure risk indoors, but also because indoor pollution has its unique transport mechanims and characteristics. In this paper, the author designed and setup a modeling experimental chamber, with the high- performance aerosol monitoring instrument, investigated the dynamic variations of candle and tobacco smoke particle concentrations which are considered as representative of indoor combustion sources of fine particles, for different diameter modes. The aim of this paper is through the basic research to reveal the transport law of indoor particles, seek efficient way for dust removal to improve indoor air quality.A reduced-scale chamber was established firstly, with aim to measure the particle concentration, the size distribution and the time series data quantitatively under well-controlled conditions, and to provide qualified data for analyzing the transport mechanisms of indoor particles. The evolution of indoor particle was found to be a dynamic process in the experiments, with the size spectrum and concentration changing continuously. It was observed that the particle number within each size interval decayed continuously, after smoke was emitted into the chamber. At the same time, the particle diameter had a growing tendency. The decay of the total number and mass concentrations were both in nearly an exponential way, and the decay rate of tobacco particles was evidently slower than that of the candle smoke particles. The decay curve of the"V"shape indicated that, those particles within the diameter range of 100nm~1000nm, should be highly paid attention to for particle removal, since they were not easily deposited but were easily formed from nano-particles.Based on the experimental data and the theory of aerosol dynamics, a high-resolution size-specific indoor particle dynamic model was established, which comprised the mechanisms of coagulation, deposition and ventilation. Some parameters of indoor attributes, such as the ratio of area to volume, indoor Reynolds number and air exchange rate, were skillfully introduced to the model. The model...