THE VIRTUAL CYCLONE AS A PERSONAL RESPIRABLE SAMPLER
Resource
AEROSOL SCIENCE AND TECHNOLOGY v.31 n.6 pp.422-432
Journal
AEROSOL SCIENCE AND TECHNOLOGY
Journal Volume
v.31
Journal Issue
n.6
Pages
422-432
Date Issued
1999
Date
1999
Author(s)
CHEN, CHIH-CHIEH
Abstract
Aerosol exposure via the inhalation route is a primary
concern in occupational health. A researcher must perform
aerosol size-selective sampling because respiratory
deposition is dependent on aerosol size. The optimal
sampling instrument is therefore the one that pro,ides the
most accurate measurement of the atmospheric dust component,
thus showing the extent of a health hazard. However, the
most commonly used respirable samplers today can only meet
the 50% cut-off point and not the slope of the respirable
convention prescribed by the American Conference of
Governmental Industrial Hygienists (ACGIH), the
International Standard Organization (ISO), and the Comite
European de Normalisation (CEN). These conventional cyclones
are also found to be affected by the aerosol deposition and
accumulation on the wall of the cyclone body, which leads
to a significant decrease in aerosol penetration. In the
present study, a miniature, compact, rugged virtual cyclone,
which employs a nonimpact particle separation, was
developed and constructed to overcome the drawbacks of the
conventional cyclones. An Aerodynamic Particle Sizer (APS)
was used for measuring the particle size distributions and
the number concentrations upstream and downstream in the
conventional and the virtual cyclones. A square virtual
cyclone (21 X 21 X 10 mm, having a curvature radius of 10 mm
, outlet width of 1 mm, and inlet width of I mm) was
designed to perfectly fit the respirable convention. This
new sampler showed almost no decrease in aerosol penetration
due to particle loading when operated at a sampling dow
rate of 3.3 L/min and aerosol mass concentration of 4.6 mg/m
(3) for 3 h. Moreover, this virtual cyclone can be used with
a conventional 37 mm cassette through an adapter.
Type
journal article