S. Fourcaudot

Acoustic agglomeration of a glycol fog aerosol: Influence of particle concentration and intensity of the sound field at two frequencies

Measurements of the initial acoustic agglomeration rate averaged over the volume of the measurement chamber, Kc0, as a function of the applied acoustic power, P, and of the initial aerosol particle concentration, NT0, have been made using sound sources operating at 10 and 21 kHz. The results show that at both frequencies the acoustic agglomeration rate is directly proportional to the square of the wave velocity amplitude, i.e. Kc0 ≡ Uw2. A model that takes account of sound attenuation in progressive or standing wave situations has been devised. The results of this model are consistent with the experimental observations when the efficiency dependency of Kc0 on Uw2 is incorporated. It is also shown that an enhanced agglomeration can be achieved under standing wave conditions. The model also yields a number of non-dimensional parameters which permit comparison of measurements made in chambers with different geometry.

Characteristics of an electro-acoustic precipitator (EAP)

Abstract Results of a laboratory scale investigation to remove sub-micron particles from a gas stream, using a combined acoustic module and electrostatic precipitator (ESP), are presented. In these experiments, 1kW of electrical power is required per 1000m 3 of gas treated to increase the particle separation efficiency of the ESP from 90 to 95%.

Acoustic agglomeration of liquid and solid aerosols: a comparison of a glycol fog and titanium dioxide

Abstract Acoustic agglomeration rates of a liquid and a solid aerosol have been measured using a 21kHz sound source in a 0.6m 3 chamber. The agglomeration efficiency of a glycol fog varies from 4 to 3500 depending on the initial concentration, whereas that for a Ti0 2 aerosol lies between 5 and 20 and is independent of the initial concentration.