Abstract
The major flow through a rectangular slit virtual impactor was experimentally studied. The impactor was a two-dimensional rectangular slit dichotomous sampler. A series of experiments were performed using monodisperse liquid oleic acid particles, monodisperse solid Polystyrene Latex particles, solid polydisperse Arizona road dust particles and solid superconducting precursor powders. The critical flow rates for separation were investigated both theoretically and experimentally using the CFX 4.0 code and the newly designed virtual impactor. The tests were conducted in the laminar regime with a Reynolds number of approximately 100. The liquid oleic acid particles were aerosolized using a vibrating orifice aerosol generator (VOAG).The solid road dust particles and superconducting powder were aerosolized using a Wright dust feeder. The concentration at the outlet of the feeder was controlled by varying the pressure drop across the feeder and also providing a dilution air supply to the dispersed air. The particles were collected on 47 mm membrane filters and were analyzed using various techniques including fluorometry, optical microscopy and Coulter counter studies. The effect of mass concentration of the particles on the major flow through the impactor was also studied. However there was a limitation to the maximum amount of mass loading obtained through the Wright dust feeder as higher concentration resulted in the formation of large agglomerates. Due to the formation of agglomerates, most of the particles ended up in the minor flow and consequently the major flow decreased. The results obtained concur with the previous studies.
Gupta, Amit (2002). The study and characterization of the major flow through rectangular slit virtual impactor. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -2002 -THESIS -G84.