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Discussion Starter · #1 ·
I heard a nasty rumor the other day from a reliable source that the new combines are going to have DPF systems on them. They will not be able to be disconnected or tampered with. We have trucks with these systems on them and they have been trouble. I don't know where they would put this filter but it gets very hot. Has anyone else heard when this could be coming.
 

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You are right, John Deere engines in a couple years will be going to a DPF / EGR system. There was a advertisment/notice in the front of one of the latest The Furrow JD magazine talking about it.

Kinda the same thing as what my '08 GM Duramax has. I don't even like it for a truck... on a combine it sounds down right scary. If you have noticed the exhaust tip of a new GM diesel, it's built to act as a venturi and it is directed more straight back instead of out the side. Dealer said that if it is regenerating (burning off) it would warp the plastic panels on something like a Saturn if parked too close. So yes, it has to get very hot to burn off. I am not sure how they are going to work out this problem.

EGR is bull too, introducing a portion of burnt gases back into the engine is just harder on the engine and pollutes engine oil faster. I have heard an engine's life can be cut by up to 10% when running EGR compared to non-EGR. It is a fact that diesel engines are not as efficient with these types of emission gear. The exhaust will be cleaner but we must burn more fuel to do the same work. I just don't know...

As for my duramax, I can buy a scanner, pull the DPF and put in an EGR blocker plate then delete a couple of codes with the scanner and I am good to go and warranty is still good. I wonder if there will be a system like this for Deere...
 

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John Deere has the EGR for a some time, the DPF is like a catalytic converter.


Diesel particulate filter
From Wikipedia, the free encyclopedia
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"DPF" redirects here. For plasma focus device, see dense plasma focus.

A diesel particulate filter (top left) in a PeugeotA diesel particulate filter, sometimes called a DPF, is a device designed to remove diesel particulate matter or soot from the exhaust gas of a diesel engine. Wall-flow diesel particulate filters usually remove 85% or more of the soot, and can at times (heavily loaded condition) attain soot removal efficiencies of close to 100%. A diesel-powered vehicle equipped with functioning filter will emit no visible smoke from its exhaust pipe.

In addition to collecting the particulate, a method must exist to clean the filter. Some filters are single use (disposable), while others are designed to burn off the accumulated particulate, either through the use of a catalyst (passive), or through an active technology, such as a fuel burner which heats the filter to soot combustion temperatures, through engine modifications (the engine is set to run a certain specific way when the filter load reaches a pre-determined level, either to heat the exhaust gases, or to produce high amounts of NO2, which will oxidize the particulates at relatively low temperatures), or through other methods. This is known as "filter regeneration". Sulfur in the fuel interferes with many "regeneration" strategies, so almost all jurisdictions that are interested in the reduction of particulate emissions, are also passing regulations governing fuel sulfur levels.
 

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This is an unavoidable thing for ag equipment, but definitely not a good thing. These dpf sytems have been nothing but trouble for every machine they ended up on. As already mentioned there is the exhaust heat issue, which could be trouble for combines for obvious reasons. Then there is the required time for the regen to take place. From what I've seen only smaller trucks (Duramax, Powerstroke, etc) are able to get away with performing regen while in operation. Larger equipment requires halting work to let the system do it's thing. I can't see that being a fun thing to do in the middle of the field, possibly several times a day. And then the fuel economy issue. Every regen-equipped machine I know of has been described as pathetic for fuel efficiency when compared to non-regen predecessors. On a 3/4 ton diesel truck the regen is said to rob roughly 4 mpg or 20-25%. That would translate into a very costly fuel bill for a combine.

I, too, hope that there will ways around this when it hits production.
 

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Hve you ever seen anything that

Farmer
+ Shop
+Time
---------------

Fixed

don't worry where there is a will there is a way around anything
 

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Discussion Starter · #6 ·
My 08 Duramax hasn't caused me any down time but I agree with the comment on mileage its pathetic. We have a PX8 engine in a feed truck application where we don't ever get it out on the highway and if we can innitiate a standing regen, which usually we have to do every 10 hrs and takes us away from feeding for roughly 20 minutes, we are happy. If for any reason it doesn't allow you to do a regen it derates power to the point that it won't do its intended job and will even shut the engine down. We have had to tow this truck 65 miles to the nearest Cummins or Kenworth dealer 3 times in one year. The first time they wouldn't cover the tow bill because we tried to interupt the standing regen part way through the process with the stop button they provide in the cab. Not a fan of this apperatus either I think given the option I'll buy carbon credits next time. Ha ha
 

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my fuel company who delivers had a new freightliner this year out in the fleet, the only one with the new system, gigantic cat underneath the cab, looked like another fuel tank, it was down half the summer once temps hit near 100F, driver said anytime he had to hit an overpass loaded it would shut down the truck, nearly causing accidents on the highway, idiot light reads high ETGs, we all know cats are bad news for diesels, they are the first to go on all my rigs, along with all those high egts and milege comes back to boot.
 

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Up until may this year I worked at DAF Trucks (dutch truck building company, part of PACCAR, you might have a Peterbilt with a DAF engine in it). More specifically i worked at the testing & development center for engines as a software specialist, I was creating software to automate the optimalization of engine parameters which are set in the ECU.

Having said that, one of the last things i worked on was to try and automate calibration of a SCR-cat


SCR works very well, but within certain limits. I would say it has an advantage over EGR when it comes to durability, since it wont clog up your intercooler / inlet system with exhaust gas residue. Another advantage is that you can optimize the burn process to higher temperaturs (= more efficient, but causes more NOx to form) since you will reduce NOx in the exhaust by adding Ad Blue.

A drawback would be that you have to tank extra "fuel" in the form of Ad blue, which obviously costs money. Another drawback is that a SCR cat needs to be at a relatively high temperature to work properly, which can get difficult to maintain if a truck is driving in a town or stuck in a traffic jam... but we are talking about farm applications and combines tend to run at near-to-max load most of the time anyways
. Note that the cat can be under the hood, and exhaust temperatures are not nearly as high as after a DPF.

Take it for what it's worth but in my opinion SCR > EGR. You will still need the DPF to reduce soot though since SCR only reduces NOx, so the hazardous extreme exhaust temperatures will still be a potential issue.

On a side note, I read some replies here about having to stop & regenerate... all the testing i have ever done/ seen done took into account regenerating "on the go", having to stop for regenerating seems strange to me. I have heard stories about burning a hole in the tarmac at a traffic light after a regen cycle though...

I can elaborate much more on this topic if you like, but i don't want to make a humongous post
 

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Discussion Starter · #10 ·
Caelin, you may be just the guy I've needed to talk to. Today we had the same thing come up again on our feed truck. According to the computer we needed to do a regeneration. Our truck moves too slowly to do an auto regen. We moved it to a safe area and could not initiate a standing regen. We took it to the pavement and run it 20 miles at 65-70 mph. Still would not regen then it derated the power again and we lucked out finaly and it regenerated. What I would like to ask you is in your programing work that you were doing did you have a contingency plan in place that would allow a parameter change to accomodate slower moving and or frequently idling vehicles? We have now been told by Cummins that there may be some solutions here but they will have to charge us for any parameter changes that they may do. I feel that one of the reasons for the implementation of these rules was to generate higher revenues for the service departments. I realize you were just doing what you were hired to do, but.... I think I can speak for almost everyone I know who owns a 2008 or newer medium to heavy truck excluding the long fellows and maybe a few of them too when I say, man have you guys caused us unimaginable grief, loss of revenue, and downtime. I desparately hope someone can override this system some day.
 

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Hi Southcentralab,

I understand what you are talking about when you complain about downtime and increased costs due to fuel usage and all the extra hassle/frustration of the regeneration process. None of the engine developers actually want to put these things on the engines/exhaust, the problem is that you need to put all these devices on there to make them compliant with the increasingly rigid environmental laws. Each and every device you put on there increases the complexity of the engine as a whole by several dimensions. This causes an exponential increase in development costs, possible failures and maybe worst of all: user frustration.

You're asking me whether it's possible to disable the regeneration or disable the power reduction if you don't regenerate. It should be possible since the parameters for when/how long to regenerate are set in the ECU. I can not tell you what parameters have to be set, or how to do this because i did not work on cummins engines, nor did I work much on DPF's (created some software for calibration for them but changed job before the actual calibration started). I do know that most engine manufacturers "lock" the ECU parameters once they go in production vehicles, otherwise customers can change all kinds of values and cause malfunctions / engine destruction.

I'm not sure if this is illegal; i guess if the dealer/maintenance department do it for you it should be okay. Things that might work but are definately illegal:
- add a pipe which leads most/all gasses around the DPF rather than through it
- removing the DPF altogether.

It is likely that the sensors will cause errors if no exhaust gas is flowing through the DPF though, causing the same trouble you have now.

This is one of the drawbacks of the focus on environmental laws. I guess it's nice to be environmentally friendly, but this always comes at a cost which tends to be ignored by our governments. With all the economical problems we have now, maybe the governments will wake up and realize that before you can spend money it needs to be earned first; I don't think anyone gives a d**n about exhaust gasses in China....

I guess the easiest solution (though slightly retarded) is to drive the truck down the highway every now and then to make sure its driven under load and gets to regenerate...
 
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