EXHAUST GAS PURIFICATION APPARATUS

摘要

In an exhaust gas purification apparatus (1) that is equipped with a first exhaust gas treatment member (3) carrying an oxidation catalyst, a three-way catalyst, or a NOx absorption-reduction catalyst used for purifying the exhaust gas of an internal combustion engine, and wherein a second exhaust gas treatment member (4) having an HC absorbing function is disposed on the downstream side of the first exhaust gas treatment member (3), a heat dissipating unit (5) that lowers the temperature of the exhaust gas flowing into said second exhaust gas treatment member (4) is provided between the first exhaust gas treatment member (3) and the second exhaust gas treatment member (4). Upstream from said heat dissipating unit (5), a heat insulating structure is formed, and even further upstream a heat retaining structure is formed. In this way, in the exhaust gas purification apparatus (1) using an oxidation catalyst, a three-way catalyst, or a NOx purification catalyst and HC adsorption material (4), even in an internal combustion engine operating state during acceleration, the exhaust gas flowing into the HC adsorption material (4) can be cooled efficiently, and HC are adsorbed by the HC adsorption material (4) during the period until the temperature of the three-way catalyst or the NOx purification catalyst rises to the HC light-off temperature.