METHOD AND APPARATUS FOR CLEANING DIESEL PARTICULATE FILTERS AND FOR DIAGNOSING DAMAGE THERETO

An apparatus for pneumatic cleaning of diesel particulate filters (DPF). First and second nozzle members direct flows of compressed air into the axially-extending filter cells from both ends of the filter, the nozzle members generally being offset so as to avoid blowing directly towards one another. The flows form the nozzles impinge only relatively small areas of the end faces of the filter media, e.g., only one or a few cells at a time. The nozzle members are moved over substantially the entirety of the first and second end faces, so that as cleaning progresses compressed air is directed into substantially all of the filter cells from opposite directions. The nozzles may be translated on reciprocated arms while the filter is rotated simultaneously on a turntable or rollers, so that the nozzles sweep over the whole surface of each end; other mechanisms, such as various combinations of gears or pistons, may be used for relative movement between the nozzles and filters. Also, the nozzle members may have single or multiple nozzles. The filter and nozzles are housed within a cabinet having one or more windows therein, which enable an operator to view progress of the cleaning process and determine when it is complete. Visual observation and also enables an operator to identify filters having damaged media, as indicated by particulate material billowing from both ends of the filter due to cracked or broke axial cells. The dislodged particulate material is withdrawn from the cabinet by an exhaust duct system.