粉塵負荷及靜電量對10mm尼龍旋風器的採樣效率的影響

Effects of Particle Mass Loading and Electrostatics on Collection Efficiency of 10 mm Nylon Cyclone

本研究探求粉塵負荷及靜電量對於10mm尼龍旋風器的微粒收集效率的影響。由 於10mm尼龍旋風器的進口與其對面內壁之距離很近，在採樣流量為1.7 L/min時，其進氣速度高達580 cm/sec,固體微粒易直接撞擊於進口對面的內壁上，使得在採樣初始時大微粒的收集效率會因微粒的反彈現象而降低。然而當微粒逐漸累積於旋風器內壁時，收集效率會因反彈現象減少而增加。至於粉塵靜電效應方面，因10mm尼龍旋風器為絕緣材質，帶靜電粉塵會因靜電作用而使其收集效率比未帶電者高。本研究發現粉塵質量負荷及靜電量對於10mm尼龍旋風器的收集效率影響很大，對於粒徑在截取氣動直徑附近的微粒影響更為顯著。一般而言，微粒的質量負荷愈高，旋風器的收集效率愈高：微粒的靜電量愈高，旋風器的收集效率也愈高。如何降低10mm尼龍旋風器的收集效率受粉塵負荷及靜電量之影響是一個重要的課題，亟待解決。

Effects of particle mass loading and electrostatics on particle collection efficiency of 10 mm nylon cyclone have been investigated. Because the distance between the inlet and its opposite inner wall of the 10 mm nylon cyclone is short and the inlet velocity is as high as 580 cm/sec when the flow rate is 1.7 L/min, solid particles tend to impact directly on the inner wall near the inlet. This leads to low initial collection efficiency of large particles due to particle bounce. However, as particles accumulate on the inner wall, the collection efficiency will start to increase when particles become less likely to rebound. As to the effect of particle electrostatics, the collection efficiency of charged particles is higher than uncharged particles because nylon is a nonconductive material. In this study, we find that both particle mass loading and electrostatics have significant effects on collection efficiency of 10mm nylon cyclone, especially for particles near the cut-off aerodynamic diameter. In general, the collection efficiency of the 10mm cyclone becomes higher as particle mass loading and electrostatics increases. To reduce the effects of particle mass loading and electrostatics on collection efficiency of 10mm nylon cyclone is an important issue which deserves further investigation.