Electrostatically charged filter media incorporating an active agent
The particle collection efficiency of a fibrous filter is significantly increased by imposing a high voltage potential on electrodes placed on either side of the filter. This creates a strong electrostatic field across the filter which electrically enhances the fiber's particle collection ability. The electrostatic field strength, and particle collection efficiency, increase with the voltage employed to establish the electrostatic field. An insulated electrode as the front electrode in combination with a conductive electrode as the rear electrode enables a very high electrical potential to be imposed on the electrodes without resulting in arcing between electrodes. Pre-charging of dust particulates with the same polarity as the insulated electrodes further increase collection efficiency without resulting in a charge buildup in front of the electrodes or a blocking of airflow by particles collecting on the electrodes.