화학공학소재연구정보센터
Particulate Science and Technology, Vol.12, No.3, 207-221, 1994
A HIGH-VOLUME SMALL CUTPOINT VIRTUAL IMPACTOR FOR SEPARATION OF ATMOSPHERIC PARTICULATE FROM GASEOUS-POLLUTANTS
This paper discusses the development of an alternative technology to sample separately the gas and particulate phases of atmospheric pollutants. The key feature of this technique is the utilization of a slit nozzle virtual impactor with a small 50% cutpoint (0.1 mu m) to sample atmospheric pollutants at high flow rates (225 LPM). In contrast to the diffusion denuder/filter pack and impactor/filter pack techniques, which collect gas and particulate phases sequentially, the two phases are separated in a virtual impactor and collected independently, to eliminate sampling artifacts. The virtual impactor has been characterized in laboratory studies using fluorescent monodisperse aerosols, and in field studies by comparing its performance to the performance of a collocated dichotomous sampler. The results indicate that the minor flow (consisting of particles in the range O.l