Patent ID: 7582141

Claim:
A method for dislodging trapped particulate matter from a substrate of a diesel particulate filter (DPF) wherein the larger end of a frustoconical wall is fit to en outer circumference of one end face of the substrate, the method comprising: occluding a portion of the one end face by placing a cover over the portion of the one end face to prevent air from entering the one end of the substrate through the occluded portion; and blowing air toward the one end face through a passageway circumscribed by the frustoconical wall with sufficient pressure to force the air to enter the substrate through an unoccluded portion of the one end face, to pass through the substrate and in the process dislodge particulate matter from the substrate, and to convey the dislodged matter out of the substrate through an opposite end face of the substrate; wherein the step of placing a cover over the one end face to prevent air from entering the one end face through the occluded portion comprises placing the larger end of a cone, over the one end face to occlude an inner zone of the one end face while leaving en outer margin of the one end face that circumscribes the inner zone unoccluded so that when air is blown toward the one end face through the passageway circumscribed by the frustoconical wall, the cone directs the air to enter the substrate through the unoccluded outer margin of the one end face, pass through an outer portion of the substrate, and exit through the opposite end face, with the air dislodging particulate matter from the outer portion of the substrate during passage through the substrate and conveying the dislodged matter out of the substrate through the opposite end face; wherein the frustoconical wall is part of a DPF casing containing the substrate; wherein the step of placing an open end of the cone against the one end face comprises inserting the cone into the casing through an opening at a smaller end of the frustoconical wall and securing the cone in place with the open end of the cone against the one end face of the substrate; and placing the casing in a cleaning machine and operating the cleaning machine to blow air through the opening at the smaller end of the frustoconical wall into the casing for passage through the substrate and exiting through an opening at an opposite end of the casing after having passed through the substrate.