†Department of Energy and Environment, Chalmers University of Technology, Göteborg, Sweden.
‡CIT Energy Management AB, Göteborg 412 58, Sweden.
Environ Sci Technol. 2015 Jun 2;49(11):6891-8. doi: 10.1021/acs.est.5b00974. Epub 2015 May 15.
Previous research has demonstrated that unipolar ionization can enhance the filter performance to collect airborne particles, aeroallergens, and airborne microorganisms, without affecting the filter pressure drop. However, there is a lack of research on the long-term system performance as well as the influence of environmental and operational parameters. In this paper, both field and laboratory tests were carried out to evaluate the long-term particle collection efficiency of a synthetic filter of class M6 with and without ionization. The effect of air velocity, temperature, relative humidity, and particle concentration were further investigated in laboratory tests. Results showed that ionization enhanced the filtration efficiency by 40%-units during most of the operation time. When the ionization system was managed by periodically switching the ionizer polarity, the filtration efficiency against PM0.3-0.5 was maintained above 50% during half a year. Furthermore, the pressure drop of the ionizer-assisted M6 filter was 25-30% lower than that of a filter of class F7. The evaluation of various influencing factors demonstrated that (1) air moisture reduced the increase of filtration efficiency; (2) higher upstream particle concentration and air velocity decreased the filtration efficiency; and (3) the air temperature had very limited effect on the filtration efficiency.
先前的研究表明，单极电离可以在不影响过滤器压降的情况下增强过滤器性能，以收集空气中的颗粒、气传过敏原和空气中的微生物。然而，对于长期系统性能以及环境和操作参数的影响，还缺乏研究。本文通过现场和实验室测试评估了带和不带电离的 M6 级合成过滤器的长期颗粒收集效率。在实验室测试中进一步研究了空气速度、温度、相对湿度和颗粒浓度的影响。结果表明，在大多数运行时间内，电离使过滤效率提高了 40%-单位。当通过周期性切换离子器极性来管理电离系统时，在半年的时间内，对 PM0.3-0.5 的过滤效率保持在 50%以上。此外，离子器辅助 M6 过滤器的压降比 F7 级过滤器低 25-30%。对各种影响因素的评估表明：（1）空气湿度降低了过滤效率的提高；（2）较高的上游颗粒浓度和空气速度降低了过滤效率；（3）空气温度对过滤效率的影响非常有限。
