Investigation on Improving the Performance of the Collection Plate of Cascade Impactor
Date Issued
2004
Date
2004
Author(s)
Chen, Chun-Shu
DOI
zh-TW
Abstract
Particle bounce is the main factor that causes the reduction of collection efficiency in cascade impactor. In practice, the collection plate is usually coated with grease to reduce bounce effects. However, grease coating is not suitable in sampling of many aerosols such as those from coal combustion because it could interface with chemical and gravimetric analysis and would be ineffective in high –temperature sampling. In this study, we use a collection plate with barrier to reduce particle bounce. The height of the barrier, bH, and the distance between the centerline of the nozzle and the barrier, bL, are theoretically determined according to particle deposition patterns and the altitude of bounce. Numerical results show that the maximum value of the ratio of bL to jet diameter, , is 1 for bL/Wpd<15µm, and is approximately equal to 1mm at the position apart 1mm from the jet edge. In order to influence the deposition of particles, must be greater than 1. Experimental results show that if , the deposition of particle is interfered by the barrier and consequently the collection efficiency is lowered. Collection efficiency decreases as the ratio increases if , which is due to cross flow.
Subjects
串
式衝擊器；收集盤；收集效率
Collection Plate
Cascade Impactor
Collection Efficiency
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-93-R91522401-1.pdf
Size
23.53 KB
Format
Adobe PDF
Checksum
(MD5):d19954a85e1fe83f0d30dca3c76e2ac9