Electrostatic particle filtration.

摘要

A vacuum cleaner (10) is disclosed having an on-board electrostatic filtration device (20) for removing ultra fine particles from the suction air stream which is discharged into the vacuum cleaner's dirt collection receptacle. The electrostatic filtration device (20) includes a finely woven conductive mesh made from two electrically insulated sets of conductive filaments (22,24) between which a low voltage electrical potential difference is applied. The polarity of the electrical potential difference is periodically reversed at low frequency to assist in maintaining filtering effectiveness notwithstanding the accumulation on the mesh of significant amounts of retained particulate matter. High permitivity material (64) is incorporated between filaments (22,24) to enhance electric fields in the mesh created by the electrical potential difference.