Particulate filter, FAP and DPF as they work on diesel engines

FAP and DPF, differences what changes?



Between these two devices FAP and DPF there is a substantial difference: the FAP needs a additive which is automatically mixed with diesel to facilitate collection and subsequently eliminate the particulate.



There is also the SCR catalyst with selective reduction in diesel engines that always has the task of reducing polluting emissions, and uses it as a reducing agent AdBlue.



What is and how the FAP particulate filter works



The name FAP (Filtres à Particules) is the commercial definition of particulate filter, introduced by the group Peugeot-Citroen (PSA group) about 15 years ago on the sedan Peugeot 607. The FAP was the first particulate filter to be installed on series cars.



Cerina that makes the FAP work



The Particulate Filter uses the as an additive cerina, trade name of the cerium dioxide (CeO2), which forms larger agglomerations of particulate matter, which therefore do not escape the particulate traps. It also lowers the flammability temperature of the particulates from 600-650 ° C to 450 ° C, and with it the frequency of regenerations of the particulate filter and the temperature at which they occur, with benefits linked to the lower production of nanoparticles harmful to health. To start the regeneration of the filter, the control unit operates post fuel injections, bringing the exhaust system up to temperature to allow combustion to start solid particles accumulated in the FAP.



There cerina it is contained in a special tank e is mixed with diesel fuel directly into the fuel tank. The 5 liters of cerina with which the car leaves the factory are sufficient for the first ones 70,000 - 80,000 kilometersafter which it is necessary to refuel, which must be carried out exclusively by specialized personnel.



The FAP is therefore a simple mechanical filter, in which there are no precious metals to act as catalysts for the chemical reactions related to regeneration.


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