以海綿為衝擊介質呼吸性粉塵分徑採樣器之佳化研究

Abstract

目前對於作業場所呼吸性粉塵在採樣上的分徑準則上乃是以美國工業衛生技師協會(ACGIH)、國際標準組織(ISO)、以及歐洲標準委員會(CEN)等三個機構所共同研商協議的結果為準則。目前已發展出以多孔泡棉作為在前置分徑裝置來達成呼吸性粉塵採樣曲線之要求。此外，將海綿應用在衝擊採樣器上微粒收集介質的研究也為數多有，並顯示海綿在解決微粒撞擊衝擊面之後的彈跳現象有明顯之改善，但目前尚未有海綿孔隙數與其他特性對於衝擊收集效應影響之深入探討。海綿作為衝擊器之收集介質方面，本研究藉由改變海綿孔隙數、直徑大小、厚度與封邊套環之有無提供不同的穿透率需求，並尋求最接近呼吸性粉塵曲線之最佳組合，以達到採樣器佳化之目的。 本款採樣器在使用上仍有微粒彈跳之問題，但可藉調整海綿直徑來改變穿透率曲線之斜率，以減小微粒彈跳所造成的影響。而微粒負載後再度彈跳之問題，顯示本採樣器並不適宜用於氣膠粒徑較大的環境之中。

In order to match the ISO/CEN/ACGIH respirable sampling criteria, applying porous polyurethane foam (PUF) to impactors on particle aerodynamic size fractioning has been studied. However, one of the inherent problems of impactors is particle bounce off the collecting plates, even though a foam substrate was applied. There is no study to examine the effect of porosity of foam on fractioning and loading property. The objective of this study is to optimize a respirable aerosol sampler with foam and identifying the foam’s effects on sampling efficiency. Using PUF with a diameter of 3 mm at a flow rate of 1.8 lpm was demonstrated to meet the ISO/CEN/ACGIH respirable sampling criteria well in this study. Results also showed that particle bounce can be minimized by applying PUF as collecting substrate. However, this impactor is not suitable applying for large diameter aerosol environments because of its available time is about 15 mins.