塵爆監測預警器之研發

Development of a Dust-Explosion-Level Aerosol Monitor

在侷限作業空間內，高濃度粉塵在氧氣達必要濃度及著火源存在時，可產生粉塵爆炸，造成人員傷亡及財物損失。目前商業化的粉塵濃度監測設備普遍受限於大微粒採樣時其管線易被阻塞，及組件在高粉塵濃度下無法有效偵測粉塵濃度等問題，並不適用於侷限空間內，偵測大粒徑高濃度粉塵。本研究安置一被動式光學粉塵計（AQ-10, EDC, Haverhill, MA, USA）於一個氣膠採樣稀釋器中，即時偵測大粒徑高濃度粉塵，成為一個可偵測與預警粉塵濃度達爆炸下限之即時監測器，吾人稱之為塵爆監測預警器。經測試該氣膠採樣稀釋器之50％穿透率之微粒直徑為30μm。經實驗產生高濃度測試粉塵：SAE粉塵<34.6g/m3和麵粉<12.6g/m3評估其性能，結果顯示其量測值與標準濃度值呈良好線性相關（R2值>0.95），預期可即時偵測達爆炸下限之一般粉塵濃度。

A real-time aerosol monitor capable of monitoring and alarming high mass concentration close to dust lower explosibility limit (LEL) has been developed and evaluated. In the dust-explosion-level aerosol monitor, particles are sampled by an aerosol diluting chamber and measured with a passive light-scattering aerosol monitor (AQ-10, EDC, Haverhill, MA, U.SA.). The particle penetration efficiency in the aerosol sampling and diluting chamber was determined experimentally using monodisperse oleic acid droplets. The results showed that the 50% cutpoint diameter was equal to 30μm. Size-selective flour and SAE dust were generated by pneumatic dispersion method as test aerosols to evaluate the performance of the dust explosion aerosol monitor. In the test range (SAE dust < 34.6 g/m3, flour < 12.5 g/m3), the real-time mass concentration measured with the aerosol monitor was in line with the value determined by the standard filtration method. The value of linear relationship was greater than 0.95 for both test aerosols. Therefore, it is expected that the aerosol monitor is able to measure much higher concentration, even close to dust LELs.