US Patent 7856815 Exhaust purification system for internal combustion engine

In an exhaust purification system that purifies exhaust from a plurality of cylinder groups of an internal combustion engine, an exhaust passageway (1,51) from each cylinder group is divided into a plurality of passageways (2a, 2b, 52a, 52b/3,53). With regard to one or more of the divided exhaust passageways (3,53), the amount of exhaust passing therethrough is reduced so as to reduce the heat release to the outside from the exhaust as a whole. In this manner, the temperature of exhaust introduced into an exhaust purification device (4,54) is kept at high temperature.