US Patent 7966810 Control device and exhaust purification method of internal combustion engine

It is suppressed that nanoparticles generated in an internal combustion engine are discharged into the atmosphere. In a cylinder or an exhaust system of the internal combustion engine, microparticles having a particle diameter larger than that of the nanoparticles are generated, and the nanoparticles generated in the internal combustion engine are adsorbed by the microparticles, thereby increasing the diameter of the nanoparticles. The microparticles can be generated in the cylinder as the soot, for example. Additionally, by providing a carbon microparticle generation device in the exhaust system, the microparticles can be generated, too. By making the nanoparticles adsorbed by the microparticles and increasing the diameter of the nanoparticles, discharging of the nanoparticles can be suppressed.