Exhaust silencer for IC engine - has turbine section followed by helical screw section

摘要

The silencer has a first section which has a cylindrical casing (1) with a volute at one side. The casing contains a cylindrical rotor (4) which carries radially projecting blades (2). The exhaust gases flowing over this rotate the impeller formed by the rotor and blades and are carried towards the atmosphere without noise. A second section connected to the first section consists of a cylindrical tube through the centre of which runs a core on which a helical fin is wound as an endless spiral. The fin may be perforated. The combination of the two sections in the path of the exhaust gases reduces noise and eliminates back pressure on the engine which would otherwise reduce the output.