There are several manufacturing techniques for developing thermionic cathodes for vacuum ultraviolet(VUV) ionizers. The triple alkaline earth metal emitters(Ca-Sr-Ba) are formulated as efficient and reliable thermo-electron sources with a great many different compositions for the ionizing devices. We prepare two basic suspensions with different compositions: calcium, strontium and barium. After evaluating the electron-emitting performance for europium, gadolinium, and yttrium-based cathodes mixed with these suspensions, we selected the yttrium for its better performance. Next, another transition metal indium and a lanthanide metal neodymium salt is introduced to two base emitters. These final composite metal emitters are coated on the tungsten filament and then activated to the oxide cathodes by an intentionally programmed calcination process under an ultra-high vacuum(~10-6 torr). The performance of electron emission of the cathodes is characterized by their anode currents with respect to the addition of each element, In and Nd, and their concentration of cathodes. Compared to both the base cathodes, the electron emission performance of the cathodes containing indium and neodymium decreases. The anode current of the Nd cathode is more markedly degraded than that with In.

AbstraThis study on the High Vpltage Ionizer for Automotive to reducing of an Electrode heat deterioration. Generally, High Volatage Ionizer is effect on the life cycle because of activating high voltage of electrode needle. An electrode needle deterioration effect on coil bobin number, manufacturing process, ion characteristics, etc. Thus, this study is considering to various characteristic of high voltage ionizer more improvement in effective.

Particle collection efficiency and air cleaning capacity were tested for the two-stage electrostatic precipitator for use in indoor air cleaning systems. A wire-plate type ionizer was used as a particle charger and a dielectric film consisted of polypropylene (or polyethylene) coated metals and zigzagged metal electrodes was used as a particle collector in the electrostatic precipitator. Both particle collection efficiency and air cleaning capacity increased as increasing the applied voltage on the charger and the collector, and furthermore, as increasing the collector film width (i.e. collection area). Air cleaning capacities estimated by the product of particle collection efficiency and air flow rate were quite well consistent with the experimental ones with a proportional constant of 0.964. Ozone concentrations emitted from the charger at the applied voltages of 5.0 and 5.2 kV were less than 0.05 ppm, indoor ozone standards of UL 867-2002, KS C 9314 and SPS-KACA002-132. For the air flow rate of 11.7 m³/min, the applied floor area of 48.2 m² could be obtained when 5.2 kV and 6.0 kV were applied on the ionizer and the collector, respectively and the collector of two 15 mm polyethylene dielectric films was used.

Bioaerosols, airborne particles of biological origin, are omnipresent in the common surroundings of humans. In antimicrobial filter system, as particles or organic materials are deposited on the filter surface, the bacteria come into contact with the antimicrobial material less, and thus they can easily grow on particles or organic materials. We selected a carbon fiber ionizer which generated air ions as antimicrobial agent. Antimicrobial effect of carbon fiber ionizer on the outlet air and condensate water was tested using application of carbon fiber ionizer in a small-scale commercial air conditioner. In conclusion, the application of carbon fiber ionizer in the air conditioner showed more increasing antimicrobial efficiency.