DEVELOPMENT OF ECONOMICAL AIR FILTERS WITH HIGH COLLECTION PERFORMANCE.

随着高科技行业对高度净化空间的需求不断增加，ULPA（超低渗透空气）过滤器已被用于洁净室中，以取代传统的HEPA（高效颗粒空气）过滤器。此外，在半导体工业中，目前使用收集效率远高于ULPA和HEPA的膜过滤器来消除加压工艺气体中的颗粒物。在目前的情况下，对这些空气过滤器的下一步要求是在不牺牲其高收集效率的情况下降低其压降。在本工作中，过滤器性能的指标，定义为颗粒穿透率的对数与压力降的比值，从过滤效率和压力降两个方面来评价各种空气过滤器的过滤性能。以过滤性能指标为基础，研究了纤维过滤器和膜过滤器的过滤结构对收集性能的影响， 关于我们 瑞幸进行了调查。此外，为了考察是否能作为经济的高捕集性能的空气过滤器，对利用静电捕集粒子的驻极体过滤器的捕集性能进行了评价，结果发现：（1）减小纤维直径，（2）增加与气流方向平行的纤维的比例，和（3）通过减少粘合剂的量。关于膜过滤器，我们根据其结构将其分为五组，并发现具有纤维状结构的膜过滤器比具有孔状结构的膜过滤器具有更高的收集性能。在此基础上，提出了一种基于内流收集模型的膜过滤器收集效率预测模型。针对驻极体过滤器的捕集性能，提出了一种计算初始捕集效率的理论模型，并通过实验证明，在潮湿空气中，驻极体纤维上的电荷是稳定的，对固体和大气颗粒物的捕集效率不随含尘量的增加而降低。然而，当驻极体过滤器用于有机雾颗粒时，电荷在短时间内被中和，导致收集效率显著降低。少

With increasing demand for highly-purified space in high-tech industry, ULPA (Ultra low Penetration Air) filters have been used in clean rooms in place of the conventional HEPA (High Efficiency Particulate Air) filters. Further, in semiconductor industry, membrane filters which have collection efficiency much higher than the ULPA and HEPA are currently used to eliminate particulate matter from pressurized process gases.Under these present situations, the next requirement for these air filters is to reduce their pressure drop without sacrificing their high collection efficiency.In the present work, an index for filter performance, defined as the ratio of logarithm of particle penetration to pressure drop was introduced to evaluate collection performance of various air filters by taking account of both the filter collection efficiency and the pressure drop. On the basis of the filter performance index, the influence of filter structure of fibrous and membrane filters on the collection pe … More rformance was investigated. Furthermore, the collection performance of electret filter which utilizes electrostatic Charge to collect particles was evaluated in order to examine whether it can be used as an economical high collection performance air filter.As a result, it was found that the collection performance of fibrous air filter can be improved (1) by reducing the fiber diameter, (2) by increasing the fraction of fibers which lie parallel to airflow direction, and (3) by reducing the amount of binder. Concerning the membrane filters, we classified them into five groups according to their structure, and found that the membrane filters with fiber-like structure have a higher collection performance than those with pore-like structure. Further, the collection efficiency of membrane filters with a relatively high-packing density was predicted by a newly proposed model based on internal flow collection model. Concerning the collection performance of electret filters, we presented a theoretical model to calculate initial collection efficiency, and experimentally showed that the electret charge on the elect fiber is stable in humid air and that the collection efficiency for solid and atmospheric particles do not decrease with dust load. However, when the electret filter was used for organic mist particles, the charge was neutralized in a short time, leading to a significant decrease in the collection efficiency. Less