| Summary: | 碩士 === 國立臺北科技大學 === 環境工程與管理研究所 === 107 === This study evaluated the characteristics and filtration performance of common filter materials Glass fiber, polytetrafluoroethylene, polypropylene, and two commercially available polypropylene filters. Analyze the surface characteristics, charge, and packing density of the filter material. The fiber diameter and pore size have a corresponding relationship: PTFE<Glass fiber<PP. The surface voltage of the filter medium is measured, and Glass fiber and PTFE are hardly electrostatic; the PP filter medium is usually an electret electret, which can maintain a stable surface voltage of about -0.30 kV after charging by negative electric corona discharge. Evaluating the performance of each filter material, Glass fiber and PFFE filter media have a pressure loss of approximately 500 to 600 Pa at a test air velocity of 0.10 m/s, and PP media have a relatively low pressure loss of only 30 to 80 Pa. All filter media have good filtration performance, of which the average filtration efficiency of PTFE filter is 99.067%, the average filtration efficiency of Glass fiber filter is 98.234%, the average filtration efficiency of PP filter is between 95.836-98.732%; the filter efficiency of PP filter after removing static electricity Both are significantly lower, ranging from 20 to 60%. The contribution of various particle collection mechanisms to the overall efficiency of the filter was calculated using the single-fiber filtration efficiency model. The diffusion of the aerosol particles at submicron size was the main collection mechanism, and the contribution of the gravity sedimentation mechanism to the test particle size range was very low or even negligible. Filtration quality is the most commonly used method to evaluate the effectiveness of filter media, including two important factors of pressure loss and filtration efficiency. When the surface wind speed is 10 cm/s, the average of Glass fiber, PTFE, PP-M, PP-S and PP-P filter media The filtration quality was 0.007 （1/Pa）, 0.009 （1/Pa）, 0.1495 （1/Pa）, 0.0642 （1/Pa）, and 0.0487 （1/Pa）, respectively. Filtering of the Glass fiber and PTFE filter was performed after removing the filter material static electricity. With the same quality, the average filter quality of PP-M, PP-S and PP-P filters was reduced to 0.017 （1/Pa）, 0.03 （1/Pa） and 0.02 （1/Pa）, respectively. Although PP in the original filter media has high filtration quality, it still needs to be considered. With the accumulation of particles and long-term use, electrostatic adsorption gradually loses its effect, resulting in reduced performance and shortened service life.
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