Patent ID: 7316735

Claim:
An apparatus for collecting particulate matter contained in a gas flowing through a flow path formed in a cylindrical shape having an outer surface and an inner surface, the apparatus comprising: an outer shell that forms the outer surface of the flow path; a ground electrode that forms the inner surface of the flow path; a filter layer that is arranged between the outer shell and the ground electrode; and a discharge electrode that generates, when a voltage is applied, an ion wind inducing a secondary flow toward the ground electrode in a direction transverse to the flow path, wherein the ground electrode includes an aperture that allows the secondary flow to pass through the ground electrode in the direction transverse to the flow path, and the filter layer includes a first aperture that allows the secondary flow to pass through the filter layer in the direction transverse to the flow path; and a second aperture that allows the secondary flow to pass through the filter layer along the flow path.