| Summary: | 碩士 === 國立臺灣大學 === 生物產業機電工程學研究所 === 99 === Indoor air quality is much more important in recent years. The purpose of this study is to set up two novel air-cleaning devices to purify specific air pollutants. The principles of air-cleaning device are photocatalysis and ultraviolet germicidal irradiation separately.
In photocatalyst study, styrofoam balls coated by TiO2 were illuminated by ultraviolet. The wavelength of ultraviolet were 254 nm and 365 nm separately. Air-cleaning device put in sampling chamber for testing process. Air pollutant was detected by direct reading instrument. However, the acetone degradation rate of photocatalysis in initial concentrations 750 ppm, 500 ppm and 250 ppm were investigated. Besides, the efficiency was compared with filter. The results showed that volume 100 ml styrofoam balls had the highest degradation efficiency were 4.8% for acetone which was better than volume 60 ml styrofoam balls 3.9% and filter 2.1% in ultraviolet wavelength 365 nm condition. The results showed that average acetone degradation rate was 30% in lower flow rate. Besides, the acetone initial concentration was 750 ppm in single circulation method and ultraviolet wavelength 254 nm conditions.
In ultraviolet germicidal irradiated study, a cyclone was installed with a 254 nm germicidial lamp. Furthermore, the residence time and the trajectories in device were simulated from computational fluid dynamics software. Besides, the volume flow rate was 60 lpm in cyclone entrance. The results showed that in 4、8 and 16 trajectories were 6.4 s, 5.7 s and 5.6 s in mesh number of 463239. In this study, measuring platform was set up to investigate the ultraviolet light conditions and intensities. The results showed that the average light intensity was 3.81 mW/cm2 in the72 hours of usage. Besides, the highest light intensity was concentrated on central of lamp.
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