Ozone production in electrostatic air cleaners with contaminated electrodes

Wind tunnel tests were conducted to assess independently the contributions of contaminated wires and plates to ozone production in positive-polarity, wire-plate air cleaners. After one week of operation in filtered air containing Arizona road dust, ozone concentration in a laboratory air cleaner increased by 460%. In this case, there was slight contamination on the discharge wires, but the ozone increase is attributed exclusively to back corona on the collection plates. Oxidized discharge wires were believed to contribute to an order of magnitude increase in ozone concentration in a commercial air cleaner operated in room air for seven weeks. It was found that wire contamination alone can increase ozone generation. An insulating tape adhesive applied to a 0.254 mm-diameter stainless steel wire caused a tenfold increase in ozone concentration. Scanning electron microscopy and energy dispersive spectroscopy were used to characterize contaminate morphology and elemental composition.<>