Patent ID: 6789385
Filing Date: 2004-09-14
Classification: F01N,Y02T

Abstract:
A reciprocating engine (2) including an exhaust system, the exhaust system comprising an exhaust pipe (8) which communicates with a silencer (10), whose upstream portion (11) is divergent in the direction of gas flow through it, an oxidising catalyst (12) and an air supply pipe (14) communicating with the exhaust pipe at a position upstream of the catalyst and silencer, characterised in that the air supply pipe (14) includes a Reed valve (16), that the Reed valve is adapted to open under a pressure differential to permit air to flow into the exhaust pipe (8) and that 3L2âˆ’(2L1+L2) is equal to Â±0.25 to 0.5 m, wherein L1 is the distance from the junction of the exhaust pipe (8) measured from a first intersection point at which the axes of the exhaust pipe (8) and the air supply pipe (14) intersect, to a point midway along the length in the flow direction of the said upstream portion (11) of the silencer (10) and L2 is the length of the air supply pipe (14) from the Reed valve (16) to the said first intersection point.