EXHAUST EMISSION CONTROL DEVICE

摘要

PROBLEM TO BE SOLVED: To stably and effectively recover from sulfur poisoning of a NOx storage catalyst without causing excessive temperature rise of the NOx storage catalyst.

SOLUTION: The device is equipped with a NOx storage catalyst (36) and an HC supply means (48) for supplying HC into exhaust flowing into the NOx storage catalyst (36). The temperature of the NOx storage catalyst (36) is raised by supplying HC amount required to maintain the NOx storage catalyst (36) to a second temperature obtained by subtracting a temperature rise through a rich spike from a first temperature predetermined as a temperature required for an S purge of the NOx storage catalyst (36) by controlling the HC supply means (48). After that, the S purge by the rich spike is started. The HC supply is continuously executed for addition so as to carry out the rich spike.

COPYRIGHT: (C)2007,JPO&INPIT