Development of the 3-stage personal dust samplers
| Autor: | Chen-Shen Chang, 張正生 |
|---|---|
| Rok vydání: | 2005 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 93 There are three kinds of particulate masses in the workplace defined by the international community: inhalable, thoracic, and respirable particulate mass. Up to now, there are almost no personal samplers for simultaneous sampling of these three particulate mass. This study intends to use the porous impaction substrate to design and manufacture a 3-stage inertial impactor for personal sampling use so that direct measurement of the three particulate mass is possible. This sampler makes use of the fact that part of the fluid flow from the nozzle will penetrate the filter paper and the porous substrate resulting in less sharp collection efficiency than the flat plate substrate. Under the condition of a proper flow rate and resistant factor for the porous substrate, the sampling criteria of the respirable and thoracic particulate mass can be met. The sampler has an inhalable inlet as the first stage with #1 porous substrate (substrate #1). The second stage is an inertial impactor of 10 μm cutoff aerodynamic diameter with #2 porous substrate (substrate #2). The 3rd stage is an inertial impactor of 4 μm cutoff aerodynamic diameter with #3 porous substrate. The after filter is the last stage, which is called #4 substrate. The particulate mass collected on #4 substrate is called respirable mass (RM), while the sum of #4 and #3 particulate mass is called thoracic mass (TM).The sum of all particulate mass collected from #1 to #4 substrates are called inhalable mass (IM). The sampling flow rate of this sampler is designed to be 2-5 LPM. This research intends to design and manufacture this personal sampler. Also the experimental study in the laboratory for the 10 and 4 μm-cut impactors in regards to different porous substrates, different flow rates, different particle diameters will be completed. The best design and flow rate condition for the sampler to meet the international particulate sampling criteria in the workplace will be found. We designed the personal dust samplers and the experimental study had been finished. The results show that when the flow rate is 2.0 LPM, the thoracic penetration curve of the impactor with porous foam (100ppi) is very close to the criteria of ACGIH. The cutoff aerodynamic diameter is 9.44 μm and differs by 5.6 % from 10 μm of the ACGIH thoracic curve. At the same time, the respirable penetration curve is very close to the criteria of ACGIH, too. The cutoff aerodynamic diameter is 3.94 μm and differs by 1.6 % from 4 μm of the ACGIH respirable curve. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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