| 摘要 |
<p>PURPOSE:To reduce the total quantity of NOx even if the exhaust temperature is changed with the fluctuation of an engine load. CONSTITUTION:A nitrogen oxides reducing device is provided with multiple catalyst carrying filters 2a-2c, which are arranged separately inside of an exhaust pipe 1 of an engine, a temperature sensor 7 provided inside of the exhaust pipe, and means 5a, 5b for passing the exhaust selectively to the multiple catalyst carrying filters 2a-2c. The exhaust flow quantity per a volume occupied with the catalyst is changed by the exhaust temperature.</p> |
