可呼吸性個人粉塵採樣器之現場測試研究

Field Test of Personal Respirable Dust Samplers

本研究主要目的在於評估新型旋風器與10 mm 尼龍旋風器在工作場所測量可呼吸性粉塵濃度之採樣誤差，以及在實驗室測試新型旋風器之最佳採樣流量。在工作場所測試時，以Marple 個人多階衝擊器量測粉塵之粒徑分布，並根據新ACGIH 規範算出可呼吸性粉塵之標準值，以作為比較新型旋風器與10 mm 尼龍旋風器測值準確性之參考。首先在實驗室測試Marple 個人衝擊器各階收集效率與粉塵負荷之關係以了解各階截取氣動直徑變化的情形，並作為工作場所測試時修正的依據。結果發現，在液體微粒方面，收集效率受粉塵負荷之影響不大，而在固體微粒方面，收集效率隨粉塵負荷增加而降低。現場測試結果發現，製釉廠粉塵粒徑分布GSD 平均為2.73，MMAD 平均為11.1μm，在不同風速下旋風器可呼吸性粉塵測值與Marple 衝擊器標準值的平均比值為1.133（10 mm 尼龍旋風器）及1.045（新型旋風器）。隨著風速由0.8 m/s 增加至2.3 m/s，旋風器測值有較接近Marple 標準值之趨勢。而TSP 對可呼吸性粉塵比值影響不大。鉛粉廠粉塵粒徑分布GSD 平均為2.26，MMAD 平均為4.82μm，在不同風速下旋風器可呼吸性粉塵測值與Marple 衝擊器標準值的平均比值為1.069（10 mm 尼龍旋風器）及0.965（新型旋風器）。而風速與TSP 對可呼吸性粉塵比值的影響亦不大。新型旋風器流量的最佳化研究，係經由理論及實驗驗證各流量下不同的收集效率,並求出與新ACGIH 規範的採樣偏差而決定之。針對不同粉塵粒徑分布（GSD=2.5，MMAD= 2, 4, 6, 8, 10, 12μm）計算最佳化的新型旋風器採樣流量。結果發現隨著旋風器內部粉塵負荷由0 mg 增至3 mg，最佳採樣流量由1.8~2.0 L/min 減小至1.6~1.7L/min。

The study is to evaluate the sampling bias of a new cyclone and a 10 mm nylon cyclone in field sampling. The optimal flow rate of the new cyclone was also tested in the laboratory. In field sampling, the Marple personal cascade impactor was used to measure the size distribution of dusts and the size distributions were used to calculate the standard RPM (Respirable Particulate Matter) concentration according to new ACGIH criteria. The effect of mass loading on collection efficiency for each stage of Marple impactor was tested in the laboratory as a measuring reference for field sampling. We found that mass loading has little effect on collection efficiency for liquid particles; while for solid particles, collection efficiency decreases as mass loading increases. In field sampling, the average GSD is 2.73 and the average MMAD is 11.1 μm for the dust distribution in a glaze factory. The average ratio of RPM measured by cyclone to the standard RPM from Marple impactor is 1.133(10 mm nylon cyclone) and 1.045(new cyclone) at different wind speeds. As wind speed increases from 0.8 m/s to 2.3 m/s, the cyclone value approaches Marple impactor value. TSP has little effect on RPM ratio. The average GSD is 2.26 and the average MMAD is 4.82 μm for the dust distribution in the lead factory. The average ratio of RPM measured by cyclone to the standard RPM from Marple impactor is 1.069(10 mm nylon cyclone) and 0.965(new cyclone) at different wind speeds. Different wind speeds and TSP have little effect on RPM ratio. As for optimization of the flow rate of new cyclone, we produced the collection efficiency curves theoretically and experimentally at different flow rates and used them to calculate the sampling bias according to new ACGIH criteria. Assuming GSD=2.5, MMAD=2, 4, 6, 8, 10 and 12 μm, the optimal flow rate ranges from 1.8~2.0 L/min to 1.6~1.7 L/min as mass loading ranges from 0 mg to 3 mg in the new cyclone.