DES Tech News

Ever wonder what makes “Clean Diesel” clean?

Advances in filtration technology and initiatives by federal and state agencies have allowed for great strides in removing harmful pollutants from diesel engine exhaust. Diesel aftertreatment systems in their many forms are the reason, but they can be complicated to maintain and expensive to replace. That’s why it’s vital to understand how they work and best practices for maintenance and cleaning.  ERICA SCHUELLER, Fleet Editor for Vehicle Service Pros has written an excellent article on this subject.  While the article is aimed more at transportation fleet managers, it does a great job of explaining the basics of diesel aftertreatment systems.  Worth the read!

“Heavy duty diesel engine aftertreatment systems were introduced as a solution to aid in reducing both PM and NOx emissions… Generally speaking, the heavy duty diesel engine aftertreatment system has two primary components: the exhaust aftertreatment technology — which includes the diesel oxidation catalyst (DOC) and diesel particulate filter (DPF) — to reduce and mitigate PM; and a select catalytic reduction (SCR) system to reduce NOx emissions.”

How do DPFs and SCRs actually work?

“What the DOC does is it changes the chemistry in the exhaust stream, and utilizes heat to burn the soot into ash, and the DPF stores the ash until it’s time to clean and have it removed,” says John Lightner, Cummins technical sales support manager. “The SCR system, through a chemical reaction, by the introduction of the diesel exhaust fluid (DEF), changes the chemistry and eliminates the NOx and greenhouse gases, so that you have (a little water and nitrogen) coming out of the tailpipe. You’re not having the carbon dioxide coming out that gives you the greenhouse gas.”

Other areas covered are finding the root causes of aftertreatment system problems and properly managing/maintaining these systems.  Often issues with a DPF can be caused by unresolved engine issues upstream such as air or oil/fluid leaks. Excessive idling can also cause premature clogging of a DPF because high exhaust temps are needed to burn off the soot – cleaning the filter by burning off the accumulated soot – this is called passive regeneration. For a passive regeneration to happen the truck needs to be driven at highway speeds/high revs for an extended period of time.

There are two areas to address when it comes to servicing the aftertreatment system: proper diagnosis, and routine maintenance. Emission & Cooling Solutions’ Griffith advises setting a proper preventive maintenance (PM) schedule for the aftertreatment system is vital to the efficient operation of the vehicle.

Preventative measures such as replacing the gaskets and clamps regularly, scheduled DPF cleanings, and using a smoke machine to check for air leaks can extend the life of the often expensive filters. Additionally, using engine heaters to minimize cold starts can greatly help reduce the amount of soot generated.

More great information on diesel aftertreatment systems is available in the original article here.

In a recent article on FleetOwner.com, there was news of the recent EPA announcement of the Cleaner Trucks Initiative aimed at decreasing NOx emissions from heavy-duty trucks starting in 2020.

“Though there are few specifics yet, EPA said it intends to publish a rule in 2020 and wants to simplify the certification of compliance requirements for heavy-duty trucks and engines. Officials noted between 2007 and 2017, NOx emissions dropped by more than 40%, but that heavy-duty trucks will be responsible for one-third of NOx emissions from the transportation sector in 2025.

The announcement comes as California continues work on developing its own tougher truck regulations…”

Andrew Wheeler, EPA’s acting administrator, announces the Cleaner Trucks Initiative on Nov. 13.

“The Cleaner Trucks Initiative will help modernize heavy-duty truck engines, improving their efficiency and providing cleaner air for all Americans,” said Andrew Wheeler, EPA’s acting administrator. “The U.S. has made major reductions in NOx emissions, but it’s been nearly 20 years since EPA updated these standards.

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Original article contributors: Neil Abt, Josh Fisher 

Diesel Emissions Service specializes in diesel emissions parts and has been successfully navigating CARB/EPA regulations for many years. We will be keeping tabs on these and other emissions related regulations as more details become available.

In a recent article on Overdrive Online, James Jaillet wrote about a recent emissions recall affecting a large number of Cummins engines.

“Cummins has instituted a voluntary recall of roughly 500,000 model-year 2010-2015 engines, according to an announcement from the U.S. EPA. The recall involves faulty emissions systems components that cause the engines to fall out of compliance with federal emissions regulations.

The trucks and engines under the voluntary recall have seen degradation of their selective catalytic reduction systems, according to financial reports issued by Cummins. SCR systems are the exhaust aftertreatment components that use diesel exhaust fluid to curb emissions of nitrogen oxides and greenhouse gases. All manufacturers of engines for Class 8 trucks use SCR and DEF in their emissions-control systems. Engine makers adopted the technology in 2010 to meet that year’s emissions hurdles…”

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Diesel Emissions Service specializes in diesel emissions parts and has been successfully navigating CARB regulations for over 40 years. We offer training and support for all stages of this market and have installed numerous DPF systems.

DES has 6 locations ranging from Southern California to BC, Canada and are rapidly expanding. For more information on how DES can help with recall related installations of Cummins emissions control systems affected by this recall. We carry a full line of Cummins compatible emissions parts, including DPFs, DOCs, SCRs, gaskets, clamps, etc.

Link to original article >> https://www.overdriveonline.com/cummins-recalling-half-a-million-engines-on-voluntary-basis-due-to-degradation-of-emissions-control-systems/