G0610302 Effect of water mist addition on participate size of PM emitted from a laminar diffusion flame of benzene

Abstract

In this study, PM aggregation technology in high humidity field was attempted by means of water-mist addition. PM exhausting from a laminar diffusion flame formed on a small pool of benzene (C_6H_6) was used for test sample. Water mist of which peak diameter was around 10 micro-meters was co-flowed and mixed with burned gas stream containing PM. Size distribution, mass of PM and water content in PM were measured by a Scanning Mobility Particle Sizer (SMPS3936, TSI Inc.), a Low Pressure Impactor (LP-20, Tokyo Dylec Corp.) and filter method. As for the PM from benzene flame, PM diameter corresponding to a peak number concentration existed within a range of 200nm - 300nm and its number was around 4x10^7 #/cm^3. Number of PM after mixing with water-mist decreased to around 1x1O^6 #/cm^3, however its diameter range shifted from nano-meter range to micro-meter range over 5 micro-meters. This diameter shift was confirmed by the LP-20 that had wide measurable range of particle diameter. Moreover, PM captured on glass-fiber filter showed that moisture in water-mist-treated PM was extremely higher than non-treated PM. From this result, it was considered that PM aggregation with water-mist was the main reason of peak diameter shift mentioned above.