Prediction of collection efficiency of high-performance electret filters
Prediction of collection efficiency of high-performance electret filters
复制标题
高性能驻极体过滤器收集效率的预测
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
H. Emi
中科院分区：
文献类型：
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作者：
Myong;Y. Otani;N. Namiki;H. Emi
驻极体过滤器经常用于空气滤清器，因为在相同的收集效率下，它们具有比机械过滤器更低的压降。驻极体过滤器的制造商已经尝试增加驻极体纤维的电荷密度以改善收集性能。通过这些努力，高性能驻极体过滤器（HPEF）的开发和一个问题是提出了对收集效率的预测方程是否适用于这些HPEF，因为预测方程从来没有测试过这样的高电荷密度驻极体过滤器。在目前的工作中，我们测量了最近开发的HPEF的收集效率，并研究了以前的收集效率预测方程的适用性。结果，HPEF的电荷密度是先前研究的驻极体过滤器的电荷密度的20倍，并且单纤维效率接近由纤维的堆积密度确定的最大极限。此外，还发现HPEF的电荷在有机溶剂中相当稳定，用乙醇浸泡后仍能保留三分之一的电荷。在预测HPEF的捕集效率时，传统的捕集效率公式适用于诱导力捕集，但不适用于库仑力捕集，因为在没有库仑力捕集的情况下，诱导力和布朗扩散导致的单纤维捕集效率很高，接近上限。
Electret filters are frequently used in air cleaners because they have a lower pressure drop than the mechanical filters at the same collection efficiency. Manufacturers of electret filters have tried to increase the electrical charge density of electret fibers in order to improve the collection performance. Through these efforts, high-performance electret filter (HPEF) is developed and a question is raised on whether the previous prediction equations for collection efficiency are applicable to these HPEF because the prediction equations were never tested for such high charge density electret filters. In the present work, we measured the collection efficiencies of recently-developed HPEF and studied the applicability of previous prediction equations for collection efficiencies. As a result, HPEF had the electrical charge density twenty times as high as that of the previously-studied electret filter and the single fiber efficiency was close to the maximum limit determined by the packing density of fibers. Furthermore, it is found that the electrical charge of HPEF is fairly stable against organic solvent, leaving one-third of initial charge after soaking it with ethanol. In predicting the collection efficiency of HPEF, the conventional equation can be applied to the collection by induced force, however that by Coulombic force is not applicable because the single fiber efficiency due to induced force and Brownian diffusion is high and close to the upper limit without the collection by Coulombic force.