Flexible device for acoustic decoupling of exhaust line of diesel engine of e.g. buses to reduce nitrogen oxide emissions from exhaust gas, has tube section consisting of annular radial waves whose geometrical dimension is not constant

摘要

The device (10) has a tube section provided with an undulating wall that is formed by a succession according to a longitudinal axis of the tube section. The tube section consists of annular radial waves (12) whose maximum outer diameters (D) are identical, where the annular waves comprise a longitudinal section in semi circular shape. A geometrical dimension of the each wave is not constant according to the longitudinal axis of the tube section. Radial height (hi) of the waves decreases systematically between an input (E) and an output (S) of the device. An independent claim is also included for an exhaust line for a combustion engine.