REGENERATING METHOD FOR SOOT PARTICLE AND NITROGEN OXIDE ELIMINATING DEVICE, AND ELIMINATING METHOD FOR SOOT PARTICLE AND NITROGEN OXIDE

摘要

PURPOSE: To maintain high purging ability for a long time by burning dust captured in a filter, forming the predetermined reducing atmosphere by using the combustion, and reducing absorbed nitrogen oxide. ;CONSTITUTION: When exhaust gas is passed through a filter 5, an elimination of dust and nitrogen oxide is carried out. When a back pressure increased because of accumulation of dust or absorbing ability for nitrogen oxide exceeds the preset value, a valve 2 is switched, and inflow of the exhaust gas to the filter 5 is stopped. Then, air is fed to the filter 5 by means of a pump, and the air and the filter 5 are heated by means of a heater 4. When combustion of the dust is started following the heating, oxygen around the filter 5 is consumed. At this time, an air feeding quantity is regulated so as to make the vicinity of the filter 5 a reducing atmosphere, and consequently, nitrogen oxide is reduced on a catalyst. In this way, purging ability can be maintained for a long time.;COPYRIGHT: (C)1996,JPO