| 摘要 |
PROBLEM TO BE SOLVED: To provide an exhaust noise reducing device capable of reducing noise of exhaust gas without changing the structure of an economizer, and to provide an engine exhaust system including the exhaust noise reducing device.SOLUTION: An exhaust noise reducing device includes: a plurality of economizers 3 which are disposed in series in an exhaust system for discharging exhaust gas from an engine 5 and which recover heat from the exhaust gas; and a connecting pipe 4 connected between the economizers 3 and having a flow passage cross-sectional area larger than the exhaust gas flow passage cross-sectional area of the economizer 3. The connecting pipe 4 is chacaterized in having a length of approximately 1/4 of a wavelength λ of an exhaust pulsation frequency of the engine 5. |
