Effect of Airflow on Ion Distribution for Potential Dust Reduction Applications

Journal of Agricultural Safety and Health
  • Mitchell, Bailey W.


High levels of airborne dust and microorganisms are continuing health concerns for animals and workers in enclosed animal housing. One approach that has been used to reduce indoor dust and microorganisms involves generation of a space charge of negative air ions which will charge dust particles and cause them to be precipitated out quickly or attached to oppositely charged surfaces. Effective distribution of the negative charge for a given generator configuration is well known to be dependent on air circulation and supply voltage. Since supply voltage is fixed for a given application, ion distribution beyond the immediate vicinity of a specific ion generator will be almost entirely dependent on air circulation. In the present study, three types of negative air ion generators were tested at direct current voltages ranging from -8 kV to -15 kV and air velocities from 0 to 200 m/min to quantify their effects on ion density distribution. Ion distribution increased significantly (P ≤ 0.01) and almost proportionally with power supply voltage and with air velocity. Compared to ambient ion density levels of about -5,000 ions/cm3, a common ceiling fan was able to extend negative ion density levels of 50,000 ions/cm3 out to 3 m from the Ceiling Ionizer and the Room Ionizer System, and the In-Duct Ionizer, which operated on compressed air, was able to extend these levels out to 5 m. Since ±50,000 ions/cm3 has been demonstrated to have a lethal effect on airborne bacteria and to be effective for reducing airborne dust, the ability of common air moving devices to distribute this level of ion density 3 to 5 m away from the ion generator suggests that these devices could easily be effectively used to reduce dust and airborne microorganisms in a variety of applications with the addition of appropriate blowers or air moving devices.

Full article can be found in: Journal of Agricultural Safety and Health
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