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Today let's learn about diesel particulate filter operation in heavy-duty diesel engines.

Inside the modern heavy duty diesel engine pistons rise and fall rapidly within the engine cylinders.

Fresh air enters the combustion chamber and mixes with the fuel  that is injected this mixture is compressed,which triggers ignition ignition causes expansion that drives the piston back down generating the energy needed to turn the crankshaft.

The byproducts of combustion include solid particulate matter which is a combination of partially burned fuel and lubricant,which is a combination of partially burned fuel and lubricant which will enter the combustion chamber below the cylinder the engine oil sump.

Is filled with oil which is circulated through the engine the oil is sprayed or splashed onto the cylinder walls to lubricate components reduce friction remove contaminants and dissipate .

Heat inside the combustion cylinder the engine oil lubricates the metal to metal sliding surfaces between the piston rings and the cylinder liner  as well as removes any post combustion contaminants like soot.

It is mainly clinging onto the particulate matter and getting ready to ride into the exhaust.The exhaust gas recirculation system or EGR sends a portion of the exhaust through an exhaust cooler and then back through the intake.Manifold to help minimize nitrogen oxides or knocks in emissions.

Not all exhaust is recirculated through the EGR,the remaining exhaust runs through the after treatment system.

Fuel is also used to elevate the temperature of the exhaust system by way of a post-combustion injection into the exhaust stream as it exits the cylinder or by a fuel doser valve, which is located prior to the after treatment system.

This fuel doser is also known as the seventh injector,any fuel injected into the exhaust stream negatively impacts fuel economy because it is used to heat he after-treatment system,rather than produce power to the crankshaft.

This process of elevating the exhaust temperature,enables the dpf system to operate properly in removing the particulates.A process known as regeneration the diesel oxidation catalyst or doc.

Functions to oxidize hydrocarbons and generate the exotherm,resulting from the njected fuel the burning of the particulate matte happens in the dpf.

Provided the temperature conditions are favorable when conditions are favorable,exhaust temperatures are hot enough to burn away most of the particulate matter from the fuel and lubricant that is trapped in the dpf.

 The selective catalytic reduction system("View product detailsSCR – Kesairay")or scr also reduces nox emissions diesel exhaust fluid or def is injected into the exhaust stream.Nox traveling in the exhaust mixes with this exhaust fluid and breaks down into nitrogen and water vapor in the presence of the scr.

Catalys there are three methods of regeneration passive active and forced.let's review each,under normal driving conditions your dashboard warning lights would be off,because there is no excess back pressure from the exhaust system as combustion occurs it leaves behind particulate matter.Which is mentioned is typically hydrocarbons from fuel soot and engine oil.

That is released into the exhaust system after being oxidized in the doc.Most of

the particulate matter is burned away in the dpf ,provided the temperature  conditions are favorable.This process is called passive regeneration.However, metallic ash from the engine oil remains in the filter and continues to accumulate.

Passive regeneration is ongoing and minimally impacts equipment functionality.

The hot exhaust dash light may come on.During this process when soot and ash build up in the dpf the back pressure gauge or the ECU triggers.

An active regeneration this may happen once or multiple times a day if your work includes excessive idling or stop and go operation the hot exhaust light or dpf regen light on the dashboard will alert the driver when an active regeneration occurs the tachometer will show a slight.

Increase from the added strain and active regeneration puts on engine  performance fuel efficiency gauges will drop dramatically.

Caused by the injection of fuel directly into the exhaust system by post combustion injection or the seventh injector the equipment can continue to operate during this process but active regeneration may also be performed.While parked during active regeneration the post-combustion injection cycle or the seventh injector will automatically spray additional diesel fuel directly into the exhaust system.This will cause substantial losses in eal time and average fuel efficiency.

The fuel will oxidize in the doc, adding heat to the dpf as temperature increases,most of the remaining soot will be oxidized and expelled through the filter at this stage.

If adequate exhaust flow cannot be properly maintained through passive and  active regeneration the equipment will need to undergo a forced regeneration.

Forced regeneration removes almost all of the remaining soot trapped in the dpf,but once again metallic ash particles are left behind continuing to clog the filter through multiple cycles of regeneration.

If the dpf becomes more than 80 percent blocked the filter is considered fully   clogged and must be removed for servicing.(View all relevant sizes DPF – Kesairay)

Available now that you know what is clogging your dpf.If you need to replace a new dpf, please contact us.

For more information about our DPF solutions or to request a quote, contact us today!

Email:kesairay@proton.me
Phone: +86 13681711685
Website: www.kesairay.com

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