Condensational droplet growth of ultrafine airborne particles with non-wetting structured tube

JAE YONG LEE, Huayan Liang, Sushant Anand, Sang Young Son

University of Cincinnati

     Abstract Number: 563
     Last modified: April 4, 2011

Abstract
This investigation aims to present the water-based condensational droplet growth incorporating a porous tube with non-wetting properties. Employing the non-wetting characteristics between working liquid and material, this structure can provide highly supersaturated condition for sampled gas without flooding regardless of orientation change and movement. For validating this concept, a new structure named as evaporation-condensation tube (ECT) was constructed and tested. Validation was conducted by the visual investigation of droplet growth at the cross-section of ECT, employing the pulsed laser sheet visualization and full-field Interferometric Mie Imaging (IMI). From the focused and out-of-focused spatially-resolved droplet images, information such as number concentration, average droplet size, spatial droplet size distribution and detection efficiency could be assessed. Results show that the dependency of spatial droplet growth characteristics with conjugated effects of convection, diffusion and droplet heating was clearly visible varying with temperature and flow rate. Also presented structure has the equivalent detection efficiency and cut-off limit with commercial water-based condensation particle counters (CPC). These results present that non-wetting structured tube can provide the equivalent performance with conventional water-based CPCs and also the additional capabilities such as orientation-independency.