The particulate filter is an element of the exhaust system of a diesel power unit. The task of this device is to clean the exhaust gases from soot in order to prevent them from entering the atmosphere (about 90% does not go outside).
The use of the filter began in 2001 in freight transport. But the introduction of the Euro-5 environmental standard in 2009 obligated all automakers to put this filter element on cars of any class and type that run on diesel.
Principle of operation
The particulate filter is designed to prevent / minimize soot from entering the atmosphere. It is part of the muffler and its main task is to clean the exhaust gases. However, you should not compare this device with a catalyst, because a catalytic converter fights exhaust gases, while a filter only fights soot in them.
The particulate filter functions in two stages:
I stage - soot capture. At this stage, soot particles settle on the walls of the filter element, which in their appearance resemble cells. At the same time, soot does not remain here completely, but only particles larger than 0.5 microns. The rest of the "trifle" goes out with the gases, although the percentage of such precipitation is small - about 10%.
The particulate filter tends to clog, which negatively affects the power characteristics of the power unit. Based on this, the device must be periodically cleaned/regenerated.
Stage II: regeneration. The labor-intensive process of cleaning the cells of the filter element from soot deposits. The procedure is carried out in accordance with the regulations prescribed by the manufacturer.
Interaction with the catalytic converter
On a diesel engine (compared to a gasoline engine), for the most part, a catalyst is not used due to differences in engine ignition systems (there are no spark plugs). But large automotive concerns (VW Group) are actively working in this direction and creating combined particulate filter / catalytic converter circuits.
Combined filter design:
- the sidewalls of the body of the cleaning device are made of a catalytic material (often titanium). Through this, combustion and oxidative processes of exhaust gases (carbon monoxide, carbon dioxide) occur;
- internal cells have channels of small cross section (consist of silicon carbide), which do not let soot particles into the atmosphere.
Passive regeneration
It takes place only on a combined device, where a catalytic converter provokes a purification process through high temperatures. The particulate filter is heated to 300-500°C, at which the soot elements are oxidized and burned.
It happens like this:
- In a catalytic converter, nitrogen and oxygen form a chemical reaction. The result of the interaction is the formation of nitrogen dioxide.
- Nitrogen dioxide reacts with soot, and the output is carbon monoxide / nitric oxide.
- Final stage: oxygen forms a chemical reaction with nitric oxide/carbon monoxide. Carbon dioxide and nitrogen dioxide appear.
So the particulate filter is cleaned, but subject to long trips.
When driving short distances, the desired temperature may not be reached. In this case, forced regeneration is required, which is also provided on the diesel engine.
The cleaning procedure is carried out while driving at high engine speeds. In this way, it is possible to achieve heating of the filtration element to approximately 600O C. At this temperature, a process of chemical reactions similar to that described above takes place, followed by cleaning of the cells.
All that is required for the driver during forced regeneration is to maintain the required engine speed. Everything else happens under the supervision of the electronic system - information is read from the sensors:
At the end of the cleaning procedure, the pressure returns to its original values, which indicates the completion of the regeneration.
Filter without catalytic converter and automatic regeneration
The particulate filter may not be compatible with the catalyst. The catalytic converter in this case is in front of the filter element, and these two devices do not touch in any way. A similar scheme is used by Ford, Peugeot, Toyota and others.
Here the purification process is different. At a certain mileage (with an exact frequency of several hundred kilometers), the car's electronics independently inject a special additive (based on Cerium) into heavy fuel:
- when the particulate filter becomes clogged, the injection system delivers this additive to the combustion chambers. When exhaust gases exit, the filter element inside heats up to very high temperatures (from +650 to +750 ° C), which heats up the device;
- cerium does not interact with the fuel and passes along with the exhaust gases to the filtration device. At the moment of contact of the substance with the filter (mesh), it ignites and raises the temperature to + 900-1000 ° C;
- soot particles oxidize and burn.
This temperature regime contributes to the regeneration of the filter element. The exhaust tract remains intact due to the use of high-strength materials in it.
A special container is reserved for the fuel additive. The additive itself is designed for 100,000 kilometers, although this figure may be reduced when the vehicle is operated on low-quality fuel.
Removal
The diesel particulate filter serves only for environmental purposes, so it can be removed without any consequences for the car. Then the engine will become easier to work, and environmental standards will drop to the Euro-3 standard - which is not critical. The procedure will require some skill and effort due to the relationship of the element with the powertrain ECU.
Pros and cons
Removal benefits:
- absence of errors and emergency mode of the engine due to a clogged filter element;
- there is no need for a regeneration mode (mandatory procedure);
- reduction in fuel consumption;
- improving the dynamic performance of the car (increasing power);
- stable operation of the power unit;
- there is no need to service the filter element.
- deterioration of environmental performance. The level of soot emissions into the atmosphere rises sharply, although it is possible to pass a technical inspection;
- problems with the operation of the vehicle in countries with the mandatory requirement of the necessary environmental standards (European Union).
Removal methods
- Software flashing. By connecting the programmer, new software is installed (not providing for the presence of a filter element) on the controller. After that, the filter itself is dismantled.
The success of the operation depends on the level of professionalism of the specialists. With an unskilled approach, various failures in the operation of the power unit and unpredictable consequences are possible. - "Deceit" (emulator). A device that takes the place of a remote filter element and imitates its operation. The installation of a "trick" is controversial: on the one hand, it will become easier for the motor to work, and on the other hand, an imitation of work will save the need for regeneration in the controller's memory. Fuel consumption will remain the same.
Compliance with environmental standards often turns into additional problems for vehicle owners due to the complexity of the design of individual components and assemblies of the machine. In particular, particulate filters installed on modern diesel engines become clogged over time and quickly become unusable, due to which certain malfunctions appear in the operation of the machine. What to do in this case? There are two ways out: either remove the particulate filter or clean it, but for some reason many motorists choose the first option.
Why is the particulate filter removed
A heavily contaminated particulate filter adversely affects the performance of the entire car, and what owner will like that his car has decreased traction, fuel consumption has noticeably increased, and besides, annoying control lights are constantly lit. Of course, you can solve the issue by replacing the part, but you will have to pay a fairly decent amount for this. In such a situation, the only reasonable way out, at least from the point of view of many motorists, is to completely remove the particulate filter from the car, but not everyone thinks about the possible consequences.
According to experts, the opinion that the extraction of this part favorably affects the “well-being” of the iron horse is nothing more than a myth, because even despite temporary improvements in dynamics, problems will still appear over time.
Diesel particulate filter removal methods
There are two ways to remove a particulate filter from your car:through the physical removal of all components of the part, or through software deactivation, which is a more competent approach to the issue.
In the first case, you need to get to the location of the DPF and, using a grinder, cut out the block with the filter element itself and the catalyst. After that, a special flame arrester is installed in their place or an ordinary piece of pipe is welded. Mounting a flame arrester allows you to increase the durability of the exhaust system, in particular, and the muffler. Moreover, thanks to this device, the engine power is significantly increased, and the exhaust sound becomes much quieter.
The software removal of a diesel particulate filter is considered a more humane method of dismantling a part. It is used when they want to avoid errors in the operation of the engine ECU, which is achieved by adding an exhaust temperature sensor and a lambda probe to a piece of welded metal pipe. Also, after removing the particulate filter, you will have to perform chip tuning of the car, which eliminates black combustion products.
After completing the specified procedure, you will notice a decrease in the "capriciousness" of the motor in terms of maintenance, although you will have to forget about the manufacturer's warranty. The procedure for removing the DPF at a service station will cost about 25-30 thousand rubles, but it all depends on the complexity of the work and the location of the element itself.
What happens if you remove the filter
By removing a clogged filter from your vehicle, of course, you will solve the problem with power and fuel consumption, but at the same time, some other inaccuracies in the car will appear. Extraneous sounds when the power unit is running and incorrect display of the state of the part are just a few of them. The system will see that the diesel particulate filter is not clogged, which simply cannot be, then decides that it is simply faulty, and puts the car into "emergency" mode. To avoid all these nuances, you should reprogram (or, as people say, “reflash”) the control unit, otherwise the ECU will constantly generate fault codes. There are two main options for how to do this.
In the first case, take the “firmware” of the version of the vehicle on which the particulate filter was not installed and upload it to your control unit. However, no one can know for sure what is not yet in this firmware, and what consequences of removing the particulate filter will “come out” here. It is likely that the standard parameters of the car will not be able to "get along" with the new changes, as a result of which any other function that was not in the old program may stop working.
You can download the required firmware on the Internet, but in this case it will be impossible to predict the result at all. If such firmware works for some time, then no one will be able to guarantee its proper functioning after a year. Floating speed, an ever-shaking speedometer needle and uneven injection are far from all the possible consequences of using low-quality software.
The best way to solve a software problem is to install programs that the manufacturer uses, but supplemented with some changes made by an experienced programmer. Such software is loaded into the chip control unit using a special device - a programmer.
Did you know? The diesel particulate filter is the development of Peugeot, who installed the first diesel particulate filter in history on their 607 model year 2000.
There is another way to avoid the problems associated with removing the particulate filter. You are required to install an emulator that would simulate the presence of a new particulate filter in the machine's system. Such an electronic device sends signals identical to those of a real filter, thus deceiving the on-board computer.
Advantages and disadvantages of filter removal
Why remove the particulate filter, you have already learned, but you should always consider not only the advantages, but also the disadvantages of any action performed. The positive aspects of removing the particulate filter include:
increase in engine power and thrust (can be achieved by reducing the resistance in the exhaust pipe);
No need for expensive maintenance and filter cleaning;
Saving motor resources due to the lack of regeneration processes;
The absence of pop-up errors that are associated with the operation of the particulate filter.
As for the shortcomings, there are not so many of them. The main one is that the car ceases to comply with Euro-4 / Euro-5 standards, which means that the car will no longer pass the technical inspection, at least without additional material costs. True, if you look at the problem from the other side, then this nuance will not be so significant, especially in comparison with the cost of the part replacement procedure. We should not forget about the above-described technical problems associated with the absence of a particulate filter, which appear as a result of its removal from the vehicle.
Currently, Europe has the Euro-6 standard, and Russia has a less stringent Euro-5 standard, which regulates the emission of harmful substances into the atmosphere.
The above documents fix the limits on emissions of harmful substances for all types of passenger cars running on combustible fuels (diesel, gasoline), so in our article we will dwell in more detail on DPF particulate filters for cars using diesel (diesel oil) as fuel.
The ignition and combustion cycle of diesel fuel is significantly different from the combustion of gasoline. If high-octane mixtures burn out almost completely, then the diesel leaves a trace in the form of soot. This is what the particulate filter should remove from the exhaust.
Diesel particulate filters may have different names that vary from country to country and from brand to brand.
- So, DPF is an abbreviation for English. Designations Diesel Particulate Filter,
- FAP is an abbreviation that came from France - Filtre a Particules,
- And RPF is from RubPartikelFilter, from Germany.
Diesel particulate filter has one main purpose - to clean the exhaust gases of a diesel internal combustion engine from soot, which comes in the form of small mechanical particles ranging in size from 10 nm to 1 micron. A detailed analysis shows that these particles are compounds of carbon with water, heavy metals, sulfur and other elements.
Physically, the filter element can be made in the form of a separate housing installed in the exhaust gas system immediately after the catalytic converter. In some car models, the particulate filter and catalyst are combined into one housing.
The filter element is most often a hard material with a crystalline porous structure, for example, a ceramic matrix (silicon carbide or other compounds).
The ceramic matrix, which is responsible for cleaning exhaust gases from soot impurities, accumulates it in its pores.
This, over time, worsens its filtering properties, makes it difficult for exhaust gases to escape, which in turn creates an additional load on the engine, since the combustion chamber is not completely cleaned of combustion products.
Exhaust system with a particulate filter in a modern car For this reason, it is required regular cleaning of the DPF filter(FAP or RPF) - the so-called regeneration.
The level of contamination of the particulate filter is monitored by special sensors.
- The most common method for assessing the contamination of a particulate filter is to analyze the pressure difference between the inlet and outlet of the assembly. The higher the difference, the higher the degree of contamination (gases have difficulty passing through the grate, which causes an increase in pressure at the inlet and a decrease in the outlet).
- Another type of sensors is oxygen, they monitor the level of oxygen in the exhaust mixture, respectively, the use of two sensors at the inlet and outlet of the particulate filter allows you to assess whether the content of other impurities has decreased or not, that is, whether purification has occurred or not.
Your car dashboard display will show the corresponding error.
Most modern cars use self-regenerating filters. They need a certain mode of engine operation to start the self-cleaning process.
When the machine is driven predominantly short distances without regularly warming up the particulate filter, this can cause it to become irreversibly filled with mechanical soot particles. In this case, you can’t do without visiting a service point or even an authorized dealer’s salon, since the error code can only be eliminated at an official service center.
Shutdown and regeneration
There are two types of particulate filter regeneration:
- Passive.
- Active.
The first type of regeneration is possible only on filters with a catalytic coating. Due to the fact that normal chemical reactions for burning soot require temperatures above 600 ° C, so-called catalysts are used to accelerate and facilitate the oxidation (combustion) reaction (substances that change the conditions for the occurrence of chemical reactions without their own consumption).
Thus, the use of a platinum-coated particulate filter reduces the temperature of soot burning to the level of 300 ° C. That is, the combustion of soot using a catalyst (catalytic coating) occurs during the natural operation of the engine, completely imperceptible to the user. There is no need to run any cleaning procedure.
Active type of regeneration involves modifying engine operation or adding special additives to the fuel in order to increase the temperature of the exhaust gases at the inlet to the particulate filter by up to 600 ° C. That is, this type of regeneration requires the participation or any active actions of the owner of a diesel car (manual start of the cleaning procedure or the addition of additives).
Built-in sensors analyze the current level of contamination of the filter element, and, if necessary, signal the user about a malfunction that has occurred (indication can occur on the dashboard or through the display of the on-board computer, depending on the model of the machine and its equipment).
Upon seeing a signal about a clogged particulate filter, the user can start the regeneration procedure in manual mode.
The procedures in different car models and different manufacturers may differ in the sequence of actions, but the bottom line is that by changing the exhaust gas cycles, their temperature rises, which in turn heats up the ceramic filter grate to the desired level and burns soot.
If the procedure regeneration in manual mode for some reason does not clean the filter (simple wear of the equipment is possible, severe clogging of the ceramic matrix, frequent driving for short distances around the city, without a full warm-up of the exhaust system, when the filter cannot clean itself, etc.), the system can change error status. Now only an authorized service center can remove it.
The specialists of the technical service point, in turn, can offer to carry out a professional filter cleaning procedure (using chemicals, etc.) or completely replace the unit with a new one.
Due to the high cost of a complete replacement, some service stations offer a cheaper filter removal procedure with the installation of equipment that deceives the pollution sensor (the error can also be removed by software). This, of course, increases the emission of harmful substances into the atmosphere. We will leave the legality of the procedure on the conscience of the service station and car owners.
Should I remove the particulate filter?
On the one hand, removing the particulate filter is a one-time procedure that allows you to save on periodic replacement or cleaning of the unit, engine power increases slightly with the filter missing (since there is no resistance to exhaust gases). On the other hand, emissions are growing, and the likelihood of passing a regular state technical inspection is reduced to zero.
The car will be able to drive with an error on the display. But it is worth bearing in mind that a clogged filter increases the resistance in the exhaust pipe.
Incorrect hardware removal of the node can cause an error due to which the engine refuses to start.
It is worth leaving the particulate filter or removing it completely - it is up to each owner to decide on their own. However, one should not lose sight of the fact that in the event of a negative result during the inspection, it may be necessary to install a new unit, which means that the removal procedure is an extra unjustified expense that only delayed the inevitable replacement procedure.
particulate filter exhaust gases - a filter element of the exhaust system of a diesel car located behind the exhaust manifold. In English it sounds like Diesel Particulate Filter, and is sometimes called sapling- designed to reduce the emission of soot particles (size from 10 nm to 1 micron) into the atmosphere together with the exhaust gas. All modern diesel cars are equipped with this filter, since the accepted environmental standards "Euro 4 and 5" require its mandatory presence.
Structurally, it can be either a simple soot filter (silicon carbide cell matrix) or quite complex. Since many are combined with a catalytic converter ().
Design and principle of operation
The particulate filter is made of a special cellular filter element, the basis of which is ceramics, placed in a metal housing. The ceramic filter system consists of a large number of microscopic channels, alternately closed from one side or the other, and the walls have a porous structure through which gas passes, but soot cannot seep through. The answer to the question of where the particulate filter is located is obvious: it is built into the car's exhaust system, but the exact location already depends on the specific model.
The principle of operation of this device is quite simple. Exhaust gases seep through the porous structure of the filter element. At the same time, almost all soot particles remain at the inlet, that is, almost pure gas, devoid of heavy impurities, comes out of the car in the form of exhaust.
The principle of operation of the particulate filter. Passive and Active regeneration.
The soot particles accumulated during filtration create resistance to the exhaust gases, which in turn leads to a decrease in the power of the car engine. In this regard, any particulate filter needs periodic cleaning of soot. This process is called regeneration.
Problems with the operation of the particulate filter
There are two types of regeneration: passive and active.
Passive regeneration occurs without the participation of the driver (occurs imperceptibly). Small deposits burn out at a temperature of about 350 degrees. Such cleaning may be accompanied by sharp smoke. But in order to achieve such a desired temperature regime, it is necessary to periodically let the diesel engine run at a speed of more than 2000 rpm. duration 5 - 10 min. This type of regeneration is performed every 500 - 700 km.
Since in urban conditions, which driving mode is not always possible, there is a gradual clogging with subsequent failure.
In this regard, drivers often periodically add special additives to the fuel that allow soot to burn at lower temperatures of about 450 ° C. The use of another type of restoration of the soot plant's working capacity is caused by the corresponding stash on the dashboard, and an error will pop up during diagnostics.
The particulate filter icon (aka exhaust system malfunction) lights up in several cases: when an active regeneration of an exhaust system element is required or if it has already become unusable.
Active regeneration particulate filter occurs at temperatures above 600 degrees (the computer for protecting data from the sensors itself performs the necessary procedures), such as:
- late fuel injection;
- additional injection;
- an additional heating element is used in front of the filter;
- fuel is injected before the filter;
It is during such procedures that the exhaust heats up to this value at the maximum load of the diesel engine. After such regeneration, the performance of the particulate filter is restored.
Emergency regeneration does not start if the filter is filled with more than a certain amount of soot (about 68 gr).
But be that as it may, the resource of the exhaust gas filter is about 250 thousand kilometers. And how long it will not be necessary to completely remove or replace the particulate filter depends on the quality of the fuel and lubricants.
Symptoms of a clogged particulate filter
When the soot cleaning filter is clogged or completely out of order, the following signs will signal its condition to the driver:
Operation features
Quite often, faulty EGR valves become the cause of a particulate filter breakdown. In modern vehicles, electronic control systems automatically count the number of completed regeneration cycles and, if necessary, notify the driver of the need to replace the filter. In any case, for the normal operation of the soot plant, it is necessary to use high-quality fuel (sulfur content should not exceed the norm) that meets the requirements of the Euro-4.5 standard. Also, owners of cars equipped with such a filter should not fill in bio-diesel.
In cars equipped with a particulate filter, it is very important to use the brand of oil that is prescribed in the instructions by the manufacturer. When it does not match, the probability of its failure due to clogging with oil waste products is very high.
It is worth remembering that a car with a particulate filter requires certain rules for maintenance and operation.
Removing or disabling the particulate filter requires software intervention.
Repair features
In most cases, diesel particulate filters are not repairable devices, but they are located under the bottom of the car or near the engine, so replacing them does not look like a difficult task, but quite expensive. That is why the majority of car owners turn to service stations in order to cut out the exhaust gas purification filter, thereby violating environmental standards for emissions of harmful substances into the atmosphere. On some machines, the particulate filter can be turned off completely (if you do not install an additional resonator, then a loud exhaust sound will appear), but only where its presence and condition is not electronically controlled. This way out of the situation is called chip tuning.
Related terms
During operation of a diesel engine, as a rule, complete combustion of fuel does not occur. As a result, together with the exhaust (exhaust) gases, components harmful to humans and the environment, including soot, enter the atmosphere. To reduce the concentration of the latter, a particulate filter is used. In English option - Diesel Particulate Filter (DPF).
Design and arrangement in the system
The particulate filter belongs to the exhaust system and can be located next to the converter or combined with it into a single structure (in this case it is located near the exhaust manifold, which ensures gas filtration at maximum temperature). The device is used only in vehicles running on diesel fuel, and, unlike the catalyst, which is installed on gasoline engines, it cleans the exhaust exclusively from soot particles.
particulate filter
Structurally, the particulate filter consists of the following elements:
- Matrix. It is made of silicon carbide (ceramic) and is a system of thin channels with a cross section in the form of a square or octagon. The ends of the passages are alternately closed, and the walls have a porous structure, due to which the soot lingers inside and settles on the walls.
- Frame. Made from metal. It has an input and output channel.
- Sensors for measuring pressure (differentials at the inlet and outlet).
- Inlet and outlet temperature sensor.
Features of the operation and operation of the particulate filter
Passing through the particulate filter, contaminants settle on the walls of the matrix, resulting in the formation of purified gases at the outlet. Gradually, the filter cells fill up and clog, preventing the passage of exhaust gases. This leads to a decrease in engine power, indicating that it needs to be cleaned or replaced.
The service life of the particulate filter depends on the operating conditions of the vehicle. On average, manufacturers recommend performing a condition check every 100,000 kilometers. The actual range of filter contamination is from 50 to 200 thousand kilometers. To extend the resource, it is necessary to regularly regenerate and change the engine oil in a timely manner.
Types and tasks of regeneration
The location of the particulate filter in the exhaust system Particulate filter regeneration is a procedure for burning soot deposited in the matrix. Regeneration is of two types:
- Passive - carried out by increasing the temperature of the exhaust gases. This can be done by accelerating the engine to maximum load (about 15 minutes of driving at 3000 rpm or more) or by adding additives to diesel fuel that reduce the temperature of soot combustion.
- Active - performed when the main mode of engine operation does not provide the required indicators for passive regeneration. To do this, a forced increase in temperature is performed for a while. The temperature increase is achieved in various ways - due to late or additional injection on the exhaust stroke, an electric heater or additional additives to the fuel.
Frequent burning wears out the ceramic matrix and leads to its destruction. And since the cost of a particulate filter is quite high, it is necessary to find the most gentle mode. It is achieved by increasing the distance traveled between regeneration procedures, as well as by reducing the temperature ranges of oil combustion.
Diesel oil selection
Unsuitable oil provokes additional contamination of the filter matrix cells and pre-wear. When the engine is running, it burns along with the fuel and, in the presence of non-combustible sediment, blocks the operation of the exhaust gas cleaning system.
For diesel engines with particulate filters, ACEA (Association of European Automobile Manufacturers) has established a certain oil standard that meets environmental standards of at least Euro-4 and the rules for operating cars in general. Motor oils for modern diesel particulate filters with ACEA approval have received the C mark (C1, C2, C3, C4). They are used for cars with exhaust purification systems, and their composition allows you to extend the life of the matrix.
Is it possible to remove the particulate filter
Many motorists, wanting to get rid of the problem of constant cleaning and replacement and the additional financial costs associated with them, decide to remove the particulate filter. You can do this in several ways:
- Dismantling the device. Mechanical removal of the diesel particulate filter can slightly increase the power of the car. On the other hand, during the operation of the machine, the engine ECU will start to give an error, perceiving the absence of a filter as a malfunction.
- Making adjustments to the software of the engine ECU (updating the program to a version that does not contain information about connecting a particulate filter). The software update is performed by a special device - a programmer, but you must be sure that the new firmware will work correctly, since the consequences can be unpredictable.
- Connecting a device emulator (without changing the factory program), which sends signals to the ECU similar to the operation of a real particulate filter.
However, it should be borne in mind that the currently established Euro-5 environmental standards prohibit the operation of a car with a diesel engine without a particulate filter.
