Method and apparatus for separating fine particulate matter from exhaust gas of an internal combustion engine

摘要

A particle separator (3) is constructed without a filter. An Independent claim is included for equipment oxidizing particles from the exhaust gases of engines. The particles are separated by thermophoresis, and the surfaces of the particle separator (3) are cooled. Preferred Features: Particles are separated by thermophoresis onto surfaces colder than the gas stream. They are separated by convection with the aid of structured surfaces and/or as a result of repeated flow reversals. They are separated through diffusion into dead zones for flow, and/or in narrow flow channels. The particles are separated by a combination of all three methods: thermophoresis, convection and diffusion. To cool surfaces, a gaseous or liquid coolant is used. Additional features of claimed equipment include use of a cooled panel- or tube bundle heat exchanger. A cooled metallic catalyst substrate may be employed. Oxidation catalyst and particle separator are incorporated in an exhaust recycle system with the cooler downstream of the oxidation catalyst acting as a thermophoretic particle separator. Additional aqueous solution injection into the exhaust between oxidation catalyst and cooler acting as a particle separator, promotes cooling of the cooler surface through evaporation, with additional thermophoretic effect. The surface of the exhaust gas line is increased; it is structured by ridges, projections or wavy structures and/or by division into a number of exhaust pipes. Flow directions are constantly altered by built-in components and/or structured surfaces. Flow is swirled by baffles or special formations.