What is the diesel particulate filter?
The diesel particulate filter is an anti pollution device installed in the exhaust in most diesel vehicles on the market in the future will also be installed on gasoline vehicles.
How diesel particulate filter works?
| Its operation is to lock and maintain the exhaust gases to avoid atmospheric emissions. The engine control unit is able to calculate the state of the filter due to temperature and pressure sensors mounted before and after. When the filter is full, the temperatures and pressures of the filter increases dramatically, in this case, the controller starts the regeneration phase, it consists in modifying the original injection program by increasing the quantity of fuel to be injected that it will not be burned in the room combustion, then comes out of the engine and through the exhaust pipe up to the particulate filter, where high temperatures will provide to burn fuel and substances accumulated in the filter. The question that is not answered is: where do they go the substances contained in the fap when they are burned? and what happens chemically during regeneration? As the system can seem like a revolution in the automotive and environmental industry, we face some technical aspects that could make us change your mind on the efficiency of this system. |
Is diesel particulate filter dangerous to human health?
| The conservation of mass says, "Nothing is created, nothing lost, everything is transformed." The particulate filter contains everything that is released by the combustion of the diesel, also including metal particles and carbonaceous coming from the engine. In an engine without fap, these substances are not large enough to be considered hazardous to human health because stopping in the upper respiratory tract, are unable to penetrate into the alveoli. In an engine provided with fap these substances are burned and the molecules that escape from the filter are much smaller than the original ones, they are therefore able to bypass the filters of the respiratory tract reaching the lungs easily. The molecules that escape from a vehicle without fap are defined in terms of size PM10 (microparticles), the maximum that can cause is asthma. The molecules which escapes from a vehicle with fap are defined PM2 (nanoparticles), they induce in tumors and are identical to those produced by incinerators. The definition of this filter as "green" is incorrect because this only occurs during standard filter conditions, it is therefore not considered everything that happens later in the regeneration phase. In big cities, after its introduction in 2007 or so, have been reported a staggering increase of diseases related to fine particles and larger global health authorities have recognized the particulate filter device as dangerous to human health, much more dangerous of the old catalytic converters (€ 3). |
What happens to the injectors?
During the regeneration phase the injectors increase the frequency of their operation, often reaching the maximum limit imposed by the manufacturers. This causes an increase in temperature and an early wear than the standard life cycle.
Why the oil level rise in engines equipped with diesel particulate filter?
Not all of the added diesel in the process of regeneration goes to end up in the muffler for cleaning the filter, a part of it extruder in the engine and is mixed with the oil. This is the reason why during the maintenance of the vehicle we often find the oil level exceeds the maximum limit, obviously the oil-diesel mixture is dangerous for the engine.
What happens to turbochargers?
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The turbines of vehicles equipped with fap are forced to work at higher temperatures and less clean condition because the fap blocks the exhaust gas and facilitates the formation of hazardous substances for the engine that thanks to the recirculation valve of the exhaust gas (second main cause of failure of modern diesel vehicles) will be reintroduced in the aspiration. So through the turbo and the intake manifold will pass several times dirty mixtures which damage the components of the turbo compressor and the pressure sensors present in the intake manifold. |
Why my car can not regenerate diesel particulate filter?
| There are two types of regenerations, Automated and forced. The automatic regeneration is activated by the control unit when the vehicle meets certain requirements that vary from model to model, including vehicle speed (eg, greater than 100 km / h), engine speed (eg, greater than 2500 rpm) and filter temperature anti particulate (eg greater than 650 ° C). The regeneration process begins to bring substantial benefits to the filter after about 30 minutes, these times are ideal for vehicles that travel long distances every day, even on the highway. For those traveling short distances, the regeneration may not start or be interrupted in advance, causing clogging of the filter and the presence of errors in the framework. The errors in the context indicates to go at a workshop authorized to carry out the forced regeneration, this is activated by the diagnostic computer directly by the technicians. In positive cases, the forced regeneration solves the problem and reset the errors of the unit. If not it will be mandatory remove the fap and clean it with professional systems or even replace it with a new, replacement prices hovering around 1200-2500 euro and 150-300 Euros for cleaning the counter. Using a diagnostic tool you can check the clogging of the fap. We found that the automatic and the forced regeneration, in fact, fail to clean the filter in a complete way, the most that we are unable to verify it was lowering the level of clogging from 100% to 50%. The cleaning procedure at the counter is more expensive but also more effective. We believe that the fap is the main cause of breakdown of vehicles together with the EGR valve. |
Will you save fuel removing the diesel particulate filter?
It was verified that 7% of the fuel is used during the phase of regeneration of the filter, so it is easy to calculate the gains that you can get by excluding this system.
How can i exclude the diesel particulate filter?
The Diesel Particulate Filter system can be disabled through programming of the control unit and the temperature and pressure probes will no longer be necessary. The part of the exhaust containing the filter must be compulsorily replaced with a straight tube (downpipe) or cut and emptied of its internal to then be preheated, so as to allow the exhaust gas to be discharged without obstruction. The vehicle will no longer no regeneration, leaving forever his original injection program and therefore consumption, ultimately in diagnosis we will be hidden all the parameters involved in the particulate filter. The exclusion of the fap is illegal for vehicles approved for road use.