Acoustic agglomeration of liquid and solid aerosols : A comparison of a glycol fog and titanium dioxide
Acoustic agglomeration rates of a glycol fog and TiO(2) aerosols have been measured under identical conditions using a 21 kHz sound source in a 0.7 m3 chamber. The starting concentrations ranged from 1.0 E5 to 1.0 E7/cm3, with a mean particle aerodynamic diameter of 1 micron. The agglomeration efficiency (the ratio of particle concentration before and after sound treatment) of the glycol aerosol is strongly dependent on the initial particle concentration, varying from 4 (at an initial concentration of 2 x 1.0 E5/cm3) to 3500 (at an initial concentration of 1.0 E7/cm3). Furthermore, the aerodynamic particle size distribution is substantially modified by sound treatment. In contrast to the glycol fog, acoustic treatment of TiO(2) aerosol results in an agglomeration efficiency of only 5 to 20, with no clear dependence on the initial particle concentration. Although particles with larger aerodynamic diameters are produced, the modification of the size distribution is considerably less dramatic than that for the fog. These results are discussed with regard to fractal behaviour of the aggregate particles, possible electrostatic charging, sticking probabilities and the orthokinetic agglomeration mechanism.
Bibliographic Reference: Paper presented: European Aerosol Conference, Karlsruhe (DE), Sept. 9-20, 1991
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Record Number: 199111341 / Last updated on: 1994-12-02
Original language: en
Available languages: en