The diesel particulate filters are added to the legislation of the emissions of the vehicle in 2009.
The diesel particulate filter (sometimes called a DPF) removes particulates diesel (or soot) from exhaust gas of a diesel vehicle, therefore reducing the emissions of particulates. The diesel particulate filters usually remove more than 85% of soot.
How it works diesel particles?
Looks like particles diesel for silencer exhaust filter work by forcing the engine through a complex ceramic Hexagon structure. Since the channels of the filter is blocked in alternative ends, the gases are forced to flow through the walls of the cell to exit the filter and because the cell walls are porous, gases are allowed to pass through, but the particles are deposited on the walls. This ensures that only clean exhaust gases can exit, and the particulates are trapped in the filter. Although they must be regularly emptied to maintain productivity, this is done in two ways:
Passive regeneration
Regeneration of passive is made automatically to the type of runs, where u.s. route the exhaust gas temperature is high, but you may experience problems when cars do not reach this kind of temperature on a regular basis (which many cars are not). Therefore, manufacturers have come up with a decision called "active regeneration".
Active regeneration
Regeneration of active takes place, where the level of soot in the filter up to about 45%. ECU makes small adjustments to the time of fuel injection and the exhaust gas temperature increases. This increases the temperature of the exhaust gases, which then begins the process of regeneration, burning away soot in DPF.
Types of filter
Cordierite filters provide excellent filtration efficiency and are relatively inexpensive. As the name suggests, are made of ceramic materials, called cordierite which is used in catalytic converters. The only problem with cordierite Wall flow filters is low melting point, which has been known to melt during filter regeneration.
Filters for flow of silicon carbide wall are the second most common filter. They have a higher melting point than cordierite filters, although they are not as thermally stable.
Ceramic filters from glass are produced by mixing different types of ceramic fibres to create porous. Then can be formed any form according to different applications. The main advantage of ceramic fibre filters is that they have a lower pressure.
Metal fibre flow through filters are made by weaving metal fibers in monolithic. They have the ability to pass electricity through which can be heated monolithic regeneration objectives. This type of filter tends to be more expensive.
