Diesel Particulate Filters – all work on the same principle. Catch the particulate (or soot) in a filter and at a certain point, clean the filter (or replace it) without environmental consequences.

Here is an older article about Cummins and how their system works.

When talking about diesel particulate filters (DPFs), there is absolutely no relation between regeneration and the need for cleaning.

Apparently, a number of folks are not quite sure just what that means or if it’s actually true. A recent conversation with Zack Ellison, the director of customer support at Cummins, began by him saying, “There’s a lot of confusion in the marketplace on how regeneration relates to the need for cleaning a diesel particulate filter. The two are completely independent of each other.”

With that said, let’s go back to the beginning. In just over a half a year, to comply with 2007 emissions regulations, all new commercial diesels will be equipped with some kind of aftertreatment device, more commonly referred to as DPFs. While these devices have been widely used on transit buses for years, they’re new to the trucking industry and apparently are causing some confusion. In general, DPFs will be installed on trucks in place of mufflers and will be needed because 2007 emissions regulations dramatically limit the particulate material that can be emitted in exhaust.

Just like the mufflers they replace, DPFs come in a variety of proprietary designs. All of them will be designed to collect particulate matter without obstructing the flow of exhaust gases. And, they do their jobs very efficiently, but, like any other filter, as they collect material, back pressure will increase unless some way is incorporated in the system to control this.

“Regeneration, which takes place in the presence of heat and a precious metal catalyst in the DPF, is the name given to how we eliminate the soot or carbon from the DP,” Ellison says. “During regeneration, the trapped soot, which is carbon, is converted to carbon dioxide (CO2). Some people think that after we burn off the soot during regeneration, we’re left with ash. That’s not correct. It’s important to understand that there is no residue left behind from the regeneration operation.”

It’s also important to understand that regeneration takes place automatically. No driver input is required nor will a driver know that the process is taking place.

“Passive regeneration means that you don’t have to add anything to the exhaust stream,” Ellison says. “The heat of the exhaust, combined with heat generated by the chemical reaction within the DPF, is enough to convert the carbon to carbon dioxide.”

Active regeneration, during which a small amount of diesel fuel is injected into the exhaust, will be required only if the exhaust temperature is too low because of lightly loaded conditions. Such a situation will not be encountered in most highway applications, but might well be required in city operations where engines have lower exhaust temperatures because they are not working as hard as they are in over-the-road applications.

“I’d say, for 99 percent of our over-the-road customers, they will never need to add fuel to the exhaust stream,” Ellison says. “That, of course, is good for fuel economy. In 30 highway test vehicles, we have yet to experience the need to add fuel for regeneration.” Even in the case of active regeneration of the DPF, no driver action is required.

So what’s all the talk about cleaning DPFs? Recall we said that these filters are very good at removing any solid material from the exhaust stream. A very small portion of that material will come from the additive package in the lube oil. This is what is referred to as “ash.” The amount that gets into the exhaust is directly related to how much oil is burned in the engine and how much of the additive doesn’t burn.

To address that situation, all engine manufacturers are designing their 2007 engines to burn exceptionally little oil, and the new CJ-rated oil that will be used in these engines will decrease ash content from 1.5 percent to 1 percent.

Still, some ash will be trapped; so filters will need cleaning by reverse flow of high-pressure air in a machine designed for the task–a process that takes about an hour and a half. By law, this cannot be required in fewer than 150,000 miles.

Ellison says that Cummins systems are designed to run 200,000 to 400,000 miles before cleaning is required.

That sounds like once in a lifetime to me!

Tom Gelinas
Editorial Director
Fleet Equipment May 1, 2006

The morphing of the Dodge Sprinter into a Mercedes Sprinter is completed.

The new grille is covered by my bug screen which I am making sure it works ok before the trip to Alaska – it does!

I notice now with the Mercedes badging, I get much better MPG and my top speed is 180mph . . .

Why re-badge? Hmmm, no one seems to be able to give a good answer to that so for me, just my super-inflated, over-active ego is the justification.

On the roof you can see the Thule wind deflector I mounted to the solar panels. Gives them a less industrial look and who knows? It may actually lesson the wind drag.

All I have left to do is to add Jack’s antenna ball to the antenna!

PS. Watch the height in the woods. I have scrapped several times on tree limbs and branches. No damage that can’t be rubbed out but the potential is there – if you see low branches, slow down!

Just a reminder . . .

The Baylands, 2775 Embarcadero Road, in Palo Alto, will be the spot.

June 7, 11:00am to whenever you get tired or bored. All SMB’s, and all Sprinters from the bay area. Totally unofficial, with no planning and no respect. However, the event is homogenized, pasteurized and may be dangerous to your heath.

Hiking and biking. Checking out the birds and all. Giants on the radio. Telling lies. Looking at mods. Lots to do!

Hope to see you there.

Too hot to drive right now with Spare the Air and all that so, I’ll opt for a place where I have been and recommended by others. Sufficient parking, trails to hike if you bring family, easy on and off the freeway, and hopefully fairy centrally located (except for the North Bay :^(.

The Baylands, 2775 Embarcadero Road, in Palo Alto, http://www.cityofpaloalto.org/depts/csd/parks_and_open_space/preserves_and_open_spaces/
the_baylands.asp  will be the spot. Here is a map of the area http://www.cityofpaloalto.org/civica/filebank/blobdload.asp?BlobID=6117 and we’ll plan on parking in the area outlined in red on the photo.

Questions? You can email me: keithmessinger@comcast.net or call me 925-997-9289 (cell) but don’t call during cocktail time!

This is a totally non-official, off-the-cuff, ill-planned chance to put some names with faces. If you want something to drink bring it. Same with food.

I’ll be there about 11:00 with a metallic silver Sprinter. It is a SMB but pretty stealth.

I have invited all bay area Sprinters, don’t have to be a SMB and all area SMB, don’t have to be a Sprinter. If you know someone who would be interested please invite them. Families are ok, what ever you want is ok.

If you are coming, please post here and tell us what you will be driving.

The June 7 Bay Area Sprinter Gathering is still on. As soon as the weather cools a bit I will check out the 2 bird refuges and let you know the place.

Hope you marked it on the calendar! This won’t be an all day deal. Probably 2 or 3 hours at the most . . . of course some of us can make a party out of anything! So go for a hike, listen to a ball game, tell a few lies, show off your rig . . .

The invite is open to any SMB vehicle, Sprinter or no; any Sprinter, SMB or no.

See you there!