Improved air ionizing apparatus

An apparatus, positioned in the output passageway of an air filter, wherein said output passageway includes inlet and outlet ends and said air filter injects a stream of air into said passageway, for producing a stream of air that contains a substantial quantity of negative ions, said apparatus comprising:

• grill means covering said outlet end of said passageway for permitting the exit of said stream of air while protecting human hands from inadvertent insertion into the interior of said passageway;
• an electrically conductive strip extending around substantially all of the interior periphery of said grill means;
• at least one ionizing needle supported and projecting laterally into the interior of said passageway, a predetermined distance from said electrically conductive strip, and having a sharp point extending toward the central portion of said passageway;
• an electric circuit with means for producing a DC voltage difference of about five thousand volts between its positive and negative terminals;
• said ionizing needle being connected with said negative terminal of said electric circuit and thereby maintained with a negative charge of about five thousand volts with respect to ground and with respect to said electrically conductive strip which is connected with said positive terminal of said electric circuit;
• and
• wherein the cross-sectional area of said passageway, the volume of air per unit of time at which the air filter injects air into the passageway, and the length of said predetermined distance are such that a substantial portion of negative ions generated from said ionizing needle are swept by the air stream past said electrically conductive strip and out of said outlet end of said passageway.