Particle Filter Based on Thermophoretic Deposition from Natural Convection Flow

Particle Filter Based on Thermophoretic Deposition from Natural Convection Flow

TitleParticle Filter Based on Thermophoretic Deposition from Natural Convection Flow
Publication TypeJournal Article
Year of Publication1994
AuthorsAntonius GBM Sasse, William W Nazaroff, Ashok J Gadgil
JournalAerosol Science and Technology
Volume20
Issue3
Pagination227 - 238
Date Published01/1994
ISSN0278-6826
Abstract

We present an analysis of particle migration in a natural convection flow between parallel plates and within the annulus of concentric tubes. The flow channel is vertically oriented with one surface maintained at a higher temperature than the other. Particle migration is dominated by advection in the vertical direction and thermophoresis in the horizontal direction. From scale analysis it is demonstrated that particles are completely removed from air flowing through the channel if its length exceeds Lc = (b4g/24Kv2), where b is the width of the channel, g is the acceleration of gravity, K is a thermophoretic coefficient of order 0.5, and v is the kinematic viscosity of air. Precise predictions of particle removal efficiency as a function of system parameters are obtained by numerical solution of the governing equations. Based on the model results, it appears feasible to develop a practical filter for removing smoke particles from a smoldering cigarette in an ashtray by using natural convection in combination with thermophoresis.

DOI10.1080/02786829408959679
Short TitleAerosol Science and Technology
Refereed DesignationRefereed