Apparatus and methods reduce, and preferably prevent, contamination of a surface or component to be charged or acted upon by a corona generating device. When a voltage is applied to the corona generating device, corona winds having a plurality of corona vortices are formed. Air is pulled via at least one drawing port of the corona generating device. At least one substantially continuous air curtain is formed along a side of the corona generating device when air is pulled via the drawing port of the corona generating device. The formation of the continuous air curtain is not dependent on air being pushed into the corona generating device. Preferably the substantially continuous air curtain extends from substantially one end of the corona generating device, at least a distance equivalent to a greatest continuous total length of the plurality of corona vortices and any portion of the corona generating device situated therebetween.