Particle Filter Based on Thermophoretic Deposition from Natural Convection Flow

Date Published
01/1994
Publication Type
Journal Article
Authors
DOI
10.1080/02786829408959679
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.

Journal
Aerosol Science and Technology
Volume
20
Year of Publication
1994
Issue
3
Pagination
227 - 238
ISSN Number
0278-6826
Short Title
Aerosol Science and Technology
Refereed Designation
Refereed
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