Electronic cartridge filter

DETAILED DESCRIPTION In one aspect of the invention a series of generally parallel, alternately charged metal electrodes, aligned to receive air-flow are edge-on, used as polarizing electrodes to polarize trapping media contained between electrodes.
The trapping medium may be in the form of a fibrous dielectric pad and/or may comprise pleated panels of air permeable trapping material.
The electrodes are preferably aligned parallel to the airflow (although this is optional, to provide a polarizing, transverse field though the trapping medium.
The polarizing electrodes may be in the form of plates between which the trapping media is placed.
Alternately, polarizing electrodes may be formed right on the trapping media surface as by sheets of conductive screening or fabric.
This can also be effected by rendering surface segments of the trapping media conducting as well as by providing air permeable conductive layer laid over such surfaces.
The electrodes and trapping media may conveniently be formatted as a cartridge for ready removal and replacement.
In all of these variants, ionization may be provided upstream in the arriving airflow by a series of ionizing needles or other ionizing elements such as fine wires or conducting strings (c.
f.
U.
S.
Pat.
No.
5,573,577, Nov.
12, 1996 by the present inventor).
Such ionization charges dust particles in the air flow, enhancing further the trapping efficiency of the media present in the polarizing field formed between the oppositely charged polarizing electrodes.
Conductive surface portions may be formed on alternating sections of trapping medium constructed as a continuous surface folded into pleated panels by coating the medium with a conductive material, such as fine carbon or aluminum, preferably mixed with a binder.
Conductive surfaces may also be formed by transferring conductive panels of conductive, porous (air-permeable) media to the trapping media as by an adhesive.
With trapping media contained between polarizing electrodes, a high potential voltage source is connected to provide a polarizing potential difference between consecutive electrodes