Compact Tractor Diesel Particulate Filters (DPF)

[jeff9366]

Time to evolve an educational thread on Tier IV (final) DIESEL PARTICULATE FILTERS.

Some form of soot/particulate removal technology is required on new tractors generating over 19 kW power = 25.4794 horsepower.

DPF is used by the majority of tractor manufactures, but not all.


I intend to develop this thread over time with contributor's input.

 

[jeff9366]

By this point we all know the general premise of how the DPF works... it captures soot in a ceramic matrix... and when hot enough it burns said soot off. If the soot builds up in the matrix to a certain point - then the tractor demands we run it parked for a period of time where it makes the whole DPF REALLY HOT (the process is called regeneration or regen) and then - the process starts over.

Diesel Particulate Filter (DPF) captures exhaust particulates (soot) in a ceramic matrix. When tractor engine runs sufficiently hot, accumulated particulates burn off periodically without operator intervention. If engine is not run continuously hot long enough to burn off particulates, diesel soot accumulates in the matrix. Once heavy soot accumulates in DPF the tractor forces soot clearance with the tractor parked and throttle open to about 2,200 rpm for about sixteen minutes, which makes the DPF REALLY HOT to burn off all accumulated soot. Burning off accumulated soot, either during operation or parked is called REGENERATION.

Forty percent of my regenerations occur during operation, sixty percent parked.



Regeneration is an infrequent event for my Kubota three cylinder engine.
Generally once every sixty engine hours. (Very consistent in Florida due to warm weather.)

60 hours X 60 minutes = 3,600 minutes.

16 regeneration minutes /3,600 = .00444 = 4/10s of 1% of engine time is consumed during parked regeneration.

Fuel cost for sixteen minute parked regeneration @ 2,200 rpm ~~$1.00.



Diesel Particulate Filter supersedes tractor muffler.
At some point in time DPF needs to be replaced.
At some point in time tractors with mufflers need the muffler replaced.

 

[jeff9366]

Following summarizes cost to VW for exceeding diesel emission standards on their diesel engine cars. Not entirely germane, but somewhat so.

How much has Dieselgate cost Volkswagen?​

Dec. 23, 2018 5:33 AM ET​

|

About: Volkswagen AG ADR (VWAGY)|By: Yoel Minkoff, Seeking Alpha News Editor​

The cleanup of Volkswagen's (OTCPK:VWAGY) diesel cheating scandal will cost the automaker €5.5B in 2018, around €2B in 2019 and €1B in 2020, CFO Frank Witter told Boersen-Zeitung.

Since 2015, the German group has paid more than €27B to settle investor and consumer lawsuits, as well as regulatory fines and remedies tied to resolving excessive emissions levels in its diesel cars.

27,000,000,000 Euros = $23,700,000,000 $/US​

 

[TBone]

Thanks Jeff for an explanation of how the DPF works. I know my L2501HST doesn't have DPF but do you know if it has a computer?

 

[jeff9366]

No, I do not. Sorry.

 

[ericm979]

The 2501 uses mechanical fuel injection.

Bransons have a DPF but use mechanical injection rather than electronic like other tractors with DPF. It uses a low temp continual regen scheme rather than discrete regens with added diesel fuel. Low Temperature Diesel Particulate Filter Regeneration by Atmospheric Air Non-thermal Plasma Injection System | SpringerLink

A few Tier 4 tractors between 25 and 75 hp use DOC (Diesel Oxydation Catalyst) instead of DPF. Those have electronic fuel injection but no DPF and no regens. Mahindra is one.

The DPF or DOC is to reduce soot output. Diesel soot is tiny particles that can go way down in the lungs and don't get expelled from the lungs like larger particles. They can cause cancer and other health problems. Tier 4 also sets limits on other pollutants like NOx but at the under 75hp level those can be met by combustion chamber design and changes in injection timing. Interestingly, reducing NOx raises soot and vice versa. So the engine designer has to strike a balance.

Above 75hp the tier 4 requirements are more stringent and generally are met with a DPF and DEF (Diesel Exhaust Fluid) in an additional catalyst.

With a DPF tractor it's a good idea to run the tractor at the RPMs the manufacturer recommends most of the time and work it hard at times.

DPFs can be cleaned. Costs I've seen range from $300-600 but that's for on the road trucks. A CUT's DPF should cost less as it's smaller. If it's too clogged it may not be cleanable.

 

[JimR]

The 2501 uses mechanical fuel injection.

Bransons have a DPF but use mechanical injection rather than electronic like other tractors with DPF. It uses a low temp continual regen scheme rather than discrete regens with added diesel fuel. Low Temperature Diesel Particulate Filter Regeneration by Atmospheric Air Non-thermal Plasma Injection System | SpringerLink

A few Tier 4 tractors between 25 and 75 hp use DOC (Diesel Oxydation Catalyst) instead of DPF. Those have electronic fuel injection but no DPF and no regens. Mahindra is one.

The DPF or DOC is to reduce soot output. Diesel soot is tiny particles that can go way down in the lungs and don't get expelled from the lungs like larger particles. They can cause cancer and other health problems. Tier 4 also sets limits on other pollutants like NOx but at the under 75hp level those can be met by combustion chamber design and changes in injection timing. Interestingly, reducing NOx raises soot and vice versa. So the engine designer has to strike a balance.

Above 75hp the tier 4 requirements are more stringent and generally are met with a DPF and DEF (Diesel Exhaust Fluid) in an additional catalyst.

With a DPF tractor it's a good idea to run the tractor at the RPMs the manufacturer recommends most of the time and work it hard at times.

DPFs can be cleaned. Costs I've seen range from $300-600 but that's for on the road trucks. A CUT's DPF should cost less as it's smaller. If it's too clogged it may not be cleanable.

My local Kioti dealer told me Saturday to run my 45HP tractor at 1800 or better at all times to keep the filter from clogging. I have 350 hours on it and the tractor has only gone into regen once since I bought it 2 years ago. I did run the regen a few times recently to check the rpm problem that I was having. The dealer said my tractor only had 2% in the filter from a test that they ran last week.

 

[CMV]

That is great JimR! Mine goes about every 40 hrs. My dealer said 2000rpm, but not critical, just more frequent regen running low rpm.

Yours may have regened more and you didn’t know it. If it wasn’t for the smell, I would have never noticed mine doing it. The dash light is easy to miss in overhead sun.

Mine has developed the annoying habit of wanting to start on the way to get fuel. Driving 1/2 mile down the road to gas station it starts....meaning I have to wait or turn around and kill some time. I know I can put it off or shut down in process, but I don’t want to tempt fate so just let it do it’s thing

 

[CMV]

BTW.....good thread. I’m happy to see no mention of a heavier DPF being a critical deciding factor on purchase of machine ��

Just kidding. But I am looking forward to learning a little more about them. What I’m real curious about is “how long do they last?” Does the DPF that came on it last lifetime or after X hrs or Y regen cycles it has to be replaced. And if it does have a limited lifespan, does it have to be replaced or can you just drill it out like you could (illegally but would function) a catalytic converter on a car?

 

[pmsmechanic]

I had an interesting conversation with a mechanic friend of mine. He works for a dealership and told me that about half of the warranty calls they get are for emissions systems. Here is a example of the stupidity of it all. If the computer senses that the DEF heater isn't working properly it will turn down the horsepower of the tractor. Even in summer when a DEF heater isn't needed. It would only be a few lines of code to tell the computer to ignore the DEF heater malfunction in summer but that would be too simple so a farmer has to wait until the service mechanic can come out to fix the problem. This doesn't go over good with customers who can't get their crop off because someone was too lazy to write a few lines of code. My friend tells me that any used tractors that get sold have the emissions software deleted.