Cummins' Plans Exchange Program For PF Elements
The particulate filters for Cummins' 2007-model diesels are typical of those planned by most engine builders, with an inlet, an oxidation catalyst to handle carbon monoxide and hydrocarbons, a second filter to strip out the particulate matter, and an outlet. The particulate filter will regenerate passively or actively to burn off accumulated soot, but ash from motor oil consumed in the engine's cylinders will require periodic removal.
Usually this servicing will be done at a truck builder's dealer and at a Cummins distributor, where a technician will remove the filter element and place it on a special machine. The machine will send compressed air through the filter's honeycomb structure in a reverse direction, blowing out the ash. This might take a half hour or so. Then the filter element will be put back into the unit and the truck will be ready to go.
However, a truck owner could also do it himself by removing the ashed-up element and exchanging it for a new or cleaned-out one from Cummins. This would sidestep the machine-blow process, saving time and getting the truck back on the road more quickly. The user could stock the PF elements as he would any other filter, or could acquire them as needed from a dealer or distributor. A large fleet might buy a blow-out machine, which will be an industry standard device and not something proprietary to Cummins.
Servicing might be needed at intervals as long as 400,000 miles, Cummins says. This would be for a linehaul truck where high exhaust heat constantly cleans out the element. In local stop-and-go operations, exhaust heat will usually be lower and passive regeneration may not be sufficient. Here the service interval will be shorter and periodic active regeneration will be required. This will be done when the engine's electronic controls sense that the element is getting full, and order the injection of a small amount of diesel fuel into the exhaust just downstream of the turbocharger. The misted fuel will hit the filter and, through a chemical reaction, heat up the element and burn off soot.
Fleetguard, a Cummins company, will make the PFs and elements. Cummins is the first to announce an exchange program for the elements, which should make life a little easier for owners of 2007-model trucks and engines.
–Tom Berg
Senior Equipment Editor
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