Method and apparatus for electrostatically cleaning particulates from air

Abstract

An electrostatic air cleaner is disclosed along with a method for removing particulate matter from moving streams of air. A high voltage ionizer is used as a corona source to ionize the particulate matter as it approaches the air filter portion of the electrostatic air cleaner. The air filter uses a pair of reticulated polyether foam filters for collecting the particulate matter. The foam filters are separated by a thin, grid-like layer of semiconductive material (carbon-impregnated polycarbonate) which is raised to a very high DC voltage. The foam filters are also surrounded by thin, grid-like layers of electrically conductive material which are held at ground potential, thus creating a high-voltage electric field through each of the foam filters. The polyether foam filter media is non-deliquescent, thus preventing the high-voltage electric field from being dissipated by such imbedded water vapor, which is the cause of filter inefficiency in the prior art. The electrostatic air cleaner of the present invention has such high initial efficiency that it does not require the addition of any particulate matter to its surfaces to achieve its nominal efficiency when first put into use. The air filter can be constructed in a relatively thin, rectangular shape, or in a cylindrical cartridge for use with industrial dust collecting systems. Both shapes lend themselves for ease of installation and removal within air handling systems.