Enhanced unipolar charging of concentration-enriched particles using water-based condensational growth

Characteristics of an electrostatic precipitator for submicron particles using non-metallic electrodes and collection plates

“…Similarly to Fig. 4, the ionic concentration was increased by increasing the applied voltage in all cases, and it was also increased by increasing the number of channels used for a given applied voltage (Han et al, 2009a(Han et al, , 2009b(Han et al, , 2008a(Han et al, , 2008b. These findings are mainly due to the increased number of carbon brush ionizers and the shorter distance between the carbon brush ionizer and the ground of the charger, thus increasing the electrical field, as well as a higher current density in the charger, for a larger number of channels (Parker, 1997;White, 1963).…”

“…The carbon fiber ionizers are made of an anticorrosive material, carbon graphite, which may be utilized easily and inexpensively by applying a voltage of a few kV to a bundle of carbon fibers in order to generate ions. These can produce stable unipolar ions at sufficiently high concentrations, whilst generating negligible concentrations of ozone (Han et al, 2009a;Han, Hudda, Ning, Kim, & Sioutas, 2009b;Han, Hudda, Ning, Kim, & Sioutas, 2008a;Han, Kim, Kim, & Sioutas, 2008b). Furthermore, the PVC sheets that coat the thin metallic films are made of a thermoplastic polymer that is known to be resistant to the effects of acidic and other corrosive gases.…”

“…1 shows the charger and collection plates of the ESP that was used in the study. The carbon brush precharger was made of several carbon brush ionizers that consisted of a bundle of approximately 300 carbon fibers whose diameter was of the order of a few micrometers (Han et al, 2009a(Han et al, , 2009b(Han et al, , 2008a(Han et al, , 2008bPark, Yoon, Kim, Byeon, & Hwang, 2009). The ionizers were connected to a high-voltage power supply and were located at the center of the channels.…”

Water condensation-based nanoparticle charging system: Physical and chemical characterization

“…Unipolar sources give 25% charging at 10 nm, decreasing to 4% at 5 nm, and is less efficient than bipolar charging below 3.5 nm (Jiang et al 2011). Several investigators have explored the use of condensationally enhanced particle charging, wherein the particles above 10 nm are grown through condensation, charged and re-evaporated (Suh et al 2005;Kim et al 2006;Choi and Kim 2007;Han et al 2008), but these methods produce high charging levels, of the order of 100 charges per particle, and thus are not suitable for mobility size-selection.…”

Integration of a nonmetallic electrostatic precipitator and a wet scrubber for improved removal of particles and corrosive gas cleaning in semiconductor manufacturing industries

“…Carbon brush chargers are made of graphite, an anticorrosive material that can produce stable unipolar ions at sufficiently high concentrations while generating negligible amounts of ozone because of the fine diameters of carbon fibers. These chargers have been used in indoor and outdoor applications to generate ions as an alternative to corona discharge from thin metallic wires and spikes (Chen et al, 2006;Han et al, 2008aHan et al, , 2008bHan et al, , 2009aHan et al, , 2009b. In addition, the ground plates of general ESPs fabricated from carbon steel and stainless steel tend to easily corrode and degrade under severely corrosive conditions.…”