FIBROUS PARTICLE DEPOSITION IN A TURBULENT CHANNEL FLOW - AN EXPERIMENTAL-STUDY

The deposition rate of glass cylinders and dust paper fibers in a turb ulent duct flow was studied experimentally. The glass fibers with a mi nimum diameter of 5 mu m and the paper fibers with a minimum diameter of 1-20 mu m and aspect ratios from 4 to 20 were deposited on a flat g old plate. The particle concentration at the test section was measured with the aid of an isokinetic probe in conjunction with a digital ima ge processing technique. An oil lubricant was used on the plate to red uce the effect of particle bounce from the surface. The experimental d ata show that the deposition rate increases with an increase in fiber length and size. For a fixed minimum diameter or a fixed equivalent re laxation time, the deposition rate increases rapidly with fiber aspect ratio. When the equivalent spherical particle relaxation time is used , the deposition rate of the fibers was found to increase only slightl y with aspect ratio and resemble those of spherical particles. The mea sured deposition velocities were in good agreement with the empirical model predictions and previous data.