Catalyst muffler system

Abstract

A muffler for coupling to an exhaust port of an internal combustion engine includes a housing, a first hollow body within the housing, a catalyzer within the first hollow body, and a second hollow body within the housing. The first hollow body has an inner surface defining a first chamber and an inlet adjacent the exhaust port to admit the exhaust gas into the first chamber. The exhaust gas is exothermally treated as it flows through the catalyst in the first chamber in a direction away from the engine and passes through an outlet of the first hollow body to a second chamber. The second chamber is formed by an inner surface of the second hollow body and an outer surface of the first hollow body. The treated exhaust gas flows through the second chamber in a direction toward the engine over the outer surface of the first hollow body where a thermal reaction takes place and/or further emission reduction takes place by a catalytic coating on the outer surface of the first hollow body. The treated exhaust gas passes through an outlet of the second hollow body to a third chamber. The third chamber is formed by an outer surface of the second hollow body and an inner surface of the housing. After expanding and mixing in the third chamber, the exhaust gas is expelled from the third chamber through an outlet of the housing adjacent the engine.