Record Details

Effectiveness of a fluidized bed in filtration of airborne particulate of submicron size

ScholarsArchive at Oregon State University

Field Value
Title Effectiveness of a fluidized bed in filtration of airborne particulate of submicron size
Names Black, Charles Hartgraves (creator)
Boubel, Richard W. (advisor)
Date Issued 1966-10-07 (iso8601)
Note Graduation date: 1967
Abstract Submicron particulate (mean size of 0.52 microns) was filtered
from air at substantially atmospheric temperature and pressure by
passing air up through a bed of fluidized glass shot in a two inch column.
Removal efficiency, defined as the percentage removal of
particulate from the air stream, was essentially constant during the
life of the bed and independent of the entering concentration over the
range of 0.1 to 5 milligrams per cubic meter. Varying superficial
gas flow rates from 8.75 to 25 feet per minute and bed heights from 5
to 12 inches, resulted in filtration efficiencies ranging from about 50
to 90 percent. Removal efficiency of the fluidized bed improved with
increased bed height and decreasing superficial gas flow velocities.
Analysis of filtration mechanisms indicated that inertial impaction
forces may be considered negligible and that the predominant
effects are Brownian diffusion, direct interception and induced electrostatic
attraction. An equation is presented describing effective
filtration efficiency as a function of mean sizes of challenging aerosol
and bed material, air viscosity and density, bed height-to-diameter
ratio, and superficial gas flow velocity.
Analyses and tests indicated particulate approximately 0.5
micron in diameter to be the most difficult to remove from the air
stream by use of the fluidized bed. Filtration efficiencies were
found for both larger and smaller particles.
Genre Thesis/Dissertation
Topic Air filters
Identifier http://hdl.handle.net/1957/47529

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