| 摘要 |
<p>PURPOSE:To provide a satisfactory silencing characteristic with a small device by defining a space provided between an inflow port for dust containing gas in a casing and an opening through which the dust containing gas flows into a filter with at least a partition plate having a vent port into small spaces. CONSTITUTION:A space 11 of a casing is formed on the upper part of a filter of a particulate trap device to be defined into small spaces 11a, 11b, 11c by two partition plates 12 respectively provided with vent ports 13. Exhaust gas enters the particulate trap device from an inlet 6. While a portion of the exhaust gas flows into the filter, another portion enters the next division through the vent port 13 of the partition plate 12 to attenuate noise components in medium- low sound regions through contraction and expansion. Then, when the passage speed of the gas through the vent port 13 becomes too high, pressure loss is increased. Since noises are generated by gas flow having speed, the size of the vent port is adjusted or the number of vent ports are set to be increased so that the vent speed is 100m/sec or less.</p> |
