EXHAUST GAS PURIFIER AND OPERATING METHOD THEREOF

摘要

An exhaust gas purifier, having three or more filter units in parallel, wherein if at least one filter unit fails during its regeneration, it is compensated by the cyclic operation of the remaining filter units so that the total function of the exhaust gas purifier is practically maintained. Electric heaters 14 are provided for regenerating individual filter units 3, and valves 4 are placed either at the entrances or at the exits of the units 3. While filter units 3 with opened valves 4 trap particulates, at least one filter unit 3's valve 4 is closed to send an electric current into the heater 14 for regenerating the filter unit 3. If the detected current is beyond a predetermined range, the current supply is shut off with the valve 4 still kept closed, and another filter unit 3 is regenerated in the same manner.