EXPERIMENTAL STUDY ON THE LOADING CHARACTERISTICS OF NEEDLEFELT FILTERS WITH MICROMETER-SIZED MONODISPERSE AEROSOLS
Resource
AEROSOL SCIENCE AND TECHNOLOGY v.34 n.3 pp.262-273
Journal
AEROSOL SCIENCE AND TECHNOLOGY
Journal Volume
v.34
Journal Issue
n.3
Pages
262-273
Date Issued
2001
Date
2001
Author(s)
CHEN, CHIH-CHIEH
Abstract
In this work, three types of needlefelt filters, made of
Polyester (PE), Ryton Sulfar (RS), and Polyaramid (PA), were
tested to investigate the aerosol loading characteristics
of fabric filters when challenged with micrometer-sized
monodisperse potassium sodium tartrate (PST) particles, A
fibrous filter with packing density of 9 %, thickness of 0.
38 mm, and fiber diameter of 5.1 mum was included for
comparison. A vibrating orifice monodisperse aerosol
generator was used to produce three different sizes (5, 10,
and 20 mum) of PST particles for aerosol loading experiment.
An ultrasonic atomizing nozzle and a TSI constant output
nebulizer were used to generate polydisperse PST particles
for the aerosol penetration test. The aerosol penetration of
submicrometer-sized particles through the filters was
measured by using a Scanning Mobility Particle Sizer. An
Aerodynamic Particle Sizer was used to measure the
penetration fraction of aerosol particles larger than 0.8
mum The pressure drop across the filter was monitored by
using pressure transducers, which were calibrated against an
inclined manometer. Airflows of 5, 10, 20, and 30 cm/s were
used to study the flow dependency. The aerosol penetration
results showed that the particles larger than 3 mum did not
penetrate the clean fabric filters tested in the present
study. The loading curves (plots of pressure drop against
sampling time) displayed three regions: an initial region of
fast increase, a transition region, and a final linear
region after the dust formation point. After the formation
point of the dust cake, both fabric and fibrous filters
shared the same slope (of the loading curves). The slope of
different regions of the loading curves was determined by
many factors, such as size of challenge aerosol, face
velocity, surface treatment, and the compressibility of the
dust cake forming on the filter, The method of final surface
treatment was found to be critical to the performance of
the fabric filters, In order to avoid the unnecessary rise
in air resistance, the melting clumps formed during final
surface treatment should be as thin and narrow as possible,
just enough to support the filter bag cleaning. From the
standpoint of filter quality and energy consumption, the low
filtration velocity has to be adopted whenever possible,
because high filtration velocity not only led to lower
filter quality (in particular for submicrometer-sized
particles) but also created dust cake of lower porosity,
which caused an extra rise in pressure drop across the dust
cake.
Subjects
PRESSURE-DROP
DUST CAKE
FILTRATION
SDGs
Type
journal article