| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an exhaust gas purification apparatus which is simply constituted, which does not increase a mounting space, which can obtain an NO oxidation capacity depending on a temperature of exhaust gas, which can constantly bring a ratio of NO:NO<SB POS="POST">2</SB>closer to 50:50, namely, a state ideal for NOx removal and which can obtain a high NOx removal ratio in a wide exhaust gas temperature range, and a method for controlling the exhaust gas purification apparatus. <P>SOLUTION: In the exhaust gas purification apparatus 1, an oxidation catalytic device 10, an ammoniacal solution supply device 20 and a selective reduction-type catalytic device 30 are disposed in order from an upstream side. The exhaust gas purification apparatus is disposed in an exhaust passage 2 of an internal combustion engine. A gas diffusion device, which includes a small-diameter pipe 12 having a hole 12a for diffusion opened on an outer peripheral part and a butterfly valve 13 openably/closably provided at the outlet-side end of the small-diameter pipe 12, is provided on the inlet side of the oxidation catalytic device 11. A central part of a catalyst arranged in the oxidation catalytic device 11 has high oxidizability, and an outer peripheral side has low oxidizability. <P>COPYRIGHT: (C)2013,JPO&INPIT |
