Characteristics of a Dry Fog Ionizer

The newly developed "Dry Fog Ionizer" generates charged dry fog. The dry fog consists of very fine water droplets 8 mu m in mean diameter. This system consists of a dry fog nozzle (H.Ikeuchi & Co.,LTD.), a ring electrode for induction charging (50mm outside diameter, and 10mm thick) in front of the nozzle, and a fan for dissipating charged dry fog. The ring electrode is DC or AC-biased and fine droplets ejected from the nozzle are electrified by induction charging. The particle size of the charged water droplets are reduced through evaporation during the transporting process by air flow, and completely evaporate approximately 2m from the nozzle under normal atmospheric conditions (25 degrees C, 60%R.H.) leaving high density ions. Using this system, high density ionic space charge can be realized in a remote spot from the ionizer. By this principle, the Dry Fog Ionizer shows strong charge-eliminating ability in the region away from the ionizer. When a do bias of RV was applied to a ring electrode with the rate of water flow from the nozzle being 21/h, an ionic space-charge density of 1200nC /m(3) was able to be obtained at a distance 2m away from the ionizer, which was 10(2) times the value produced by an ordinary corona-type ionizer with an air blower.