Practically all modern diesel vehicles possess diesel particulate filters (DPF) which are fitted ex works. They usually have to be replaced after approximately 80,000 – 160,000 km. That is why ERNST maintains a comprehensive product portfolio that is constantly being updated and extended.
The exhaust gas that arises during the combustion process contains not only gaseous but also solid components, the so-called particulate matter. In diesel engines, in particular, this particulate matter contains a high proportion of soot particles. ERNST diesel particulate filters reliably ensure that these fine particles do not enter the environment.
Only wall-flow filters are used in ERNST particulate filters.
The wall-flow filter consists of ceramic modules with a large number of channels that are alternately plugged in a chess board pattern. The exhaust gas is filtered in a cyclical process: The exhaust gas flows into the channels and the gaseous matter penetrates the porous walls, whereas the solid components are blocked and deposited at the walls. The soot burns off in a continuous regeneration process and the filter is ready to absorb a new load.
If the diesel particulate filter is to remain effective in the long term, it is important that the filter is regenerated regularly. As soon as the temperature of the exhaust gas reaches 500 - 600 °C, the deposited soot ignites and burns off. The diesel particulate filter is again ready to absorb a new load. This process is repeated continuously. A distinction is made between two different regeneration processes.
Passive regeneration
Natural regeneration takes place automatically and continuously as the soot deposited on the filter burns off by itself. However, this regeneration process is only possible if the diesel particulate filter has reached the necessary operating temperature of 500 - 600 °C.
Active regeneration
In the case of dynamic, or forced, regeneration, engine management plays an active role. The load level at the filter is continuously monitored by the software in the controller. If regeneration is necessary, additional fuel is injected in order to raise the exhaust gas temperature sufficiently high for the soot on the filter to ignite and completely burn off.
As mentioned above, exhaust gas temperatures of 500 - 600 °C are required for the regeneration of the diesel particulate filter. However, these temperatures are rarely reached when driving in frequent stop-and-go traffic. Read how your driving behaviour can contribute to the active regeneration of your diesel particulate filter.
If the temperatures required for natural regeneration of the diesel particulate filter are not reached then the consequences are serious. The amount of soot deposited at the filter increases and so too does the counterpressure resisting the exhaust gas flow. This impairs both the efficiency of the engine and the vehicle’s ability to accelerate. Engine management constantly attempts to maintain the load level within a certain range. As a result, active regeneration operations are triggered more frequently. This increases fuel consumption.
Go for regular regeneration drives. In these regeneration drives, you once again reach higher exhaust gas temperatures that permit the natural regeneration of the filter. When doing this, please observe the vehicle manufacturer’s instructions for regeneration drives.
Exhaust aftertreatment in diesel engines involves an extremely complex system. The diesel particulate filter is an important component in this system. However, it can only function correctly if all the peripheral components are also working perfectly. If malfunctions occur in the system, attempting to track down the fault can quickly become a real headache.
How we support you:
If the electronic display flashes, the vehicle loses power or the fuel consumption is extremely high, then attempting to track down the fault can quickly become a real headache. We help you build up the necessary expertise for troubleshooting and repairing diesel particulate filters.
