Patent ID: 7959883

Claim:
A method of removing particles from an engine exhaust stream, the method comprising: passing an engine exhaust stream carrying suspended carbonaceous particles into a charging zone in an exhaust passageway; providing an assembly having at least one internal surface defining the exhaust passageway, the assembly including a first electrode least partially disposed in an upstream portion of the exhaust passageway forming the charging zone, and a particulate collector supporting the oppositely charged collecting surface at least partially disposed in a downstream portion of the exhaust passageway forming the collection zone; generating a corona discharge in the charging zone from the first electrode effective to produce at least some charged carbonaceous particles; applying an electrical potential to the particulate collector that is sufficient to cause at least some of the charged carbonaceous particles to be deposited on the collecting surface; passing the exhaust stream and charged carbonaceous particles from the charging zone into a collection zone downstream of the charging zone in the exhaust passageway; electrostatically attracting at least some of the charged carbonaceous particles to an oppositely charged collecting surface within the collection zone; and allowing the exhaust stream exclusive of the particles deposited on the collecting surface to exit the exhaust passageway; wherein the collecting surface comprises a catalyst, and wherein at least some of the particles deposited on the collecting surface are chemically reacted upon contact with the collecting surface.