화학공학소재연구정보센터
Journal of Chemical Engineering of Japan, Vol.44, No.8, 535-545, 2011
Theoretical and Experimental Evaluation of a Mixing-Type Bipolar Charger Using Corona-Discharge at High Pressure
A Mixing-type Bipolar Charger using Corona-discharge at High Pressure (MBCCHP) is subjected to both theoretical and experimental evaluation. In theoretical studies, the charging model for the MBCCHP is developed to determine the influences of the residence time t(R), the number ratio of negative ions to positive ions N(-)/N(+), and the number ratio of particles to bipolar ions n(0)/N(B) (where N(B) = N(+) + N(-)) on the charge distribution. The charge distribution recorded experimentally at various values of n(0)/N(B) and N(-)/N(+) is compared with theoretical results. The comparisons indicate that the theoretical results can be used to adequately explain well the experimental data. Both sets of results demonstrate that the MBCCHP is capable of generating equilibrium charge distributions of aerosol particles within errors of 10%. The diameter of the particles ranges between 10-500 nm and the particle number concentration n(0) is less than 3.0 x 10(12) m(-3) under operating conditions of 0.5 > t(R) > 0.1 s, with a frequency >100 Hz, a voltage of 9.0 kV(0-p), and a high-pressure ionizer operating at 0.4 MPa.