SYSTEM FOR EXHAUST GAS PURIFICATION AND METHOD OF CONTROLLING THE SAME

摘要

A system for exhaust gas purification (1) which comprises, disposed in the exhaust passage (11) of an internal combustion engine (10) in the following order from the upstream side: a device (47) for direct injection into the exhaust pipe, an oxidation catalyst (31), and at least one of a catalyst for NOx removal (32) and a catalyzed DPF (33). The support of the oxidation catalyst (31) comprises a metallic material or a material having a specific heat not higher than that of the metallic material, and has a structure having the function of mixing the exhaust gas. As a result, the regeneration of the NOx occlusion/reduction type catalyst (32) by NOx removal and the forced regeneration of the catalyzed DPF (33) by PM removal can be practiced even when the internal combustion engine (1) is operated under low-load conditions.