Charged fog technology. Part I. Theoretical background and instrumentation development

Water sprays, the most common method of controlling dust in mines and from fugitive emission sources, do not control inhalable particles very effectively. Since most industrial pollutants and naturally occurring fugitive dust particles acquire electric charges as they are dispersed into the air, the inhalable particle control efficiency of water sprays can be significantly improved if the water droplets are also electrically charged to the opposite polarity. Commercially available charged fog devices have several disadvantages. They require high pressure air and/or water, their nozzles are prone to clogging, and they generate charged droplets which are poorly suited for good inhalable particle control. This paper reviews the basic principles of charged fog technology and describes a new charged fog generator which overcomes the problems of commercial charged fog devices. In the charged fog generator (CFG), water from a reservoir is introduced into a rotating cup where the water forms a thin layer due to c...