Compact Tractor Diesel Particulate Filters (DPF)

[ericm979]

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?

The Branson 25 series's DPF having more catalyst (according to the dealer) was a small factor in my choosing a 25 series instead of a 20 series.

Semi trucks' DPFs are supposed to last in the 3500-5000 hour range. Their emissions systems also use DEF (and have to handle a lot more power) so they may be harder on the DPF than our < 75hp tractors. There are services that will clean a DPF- for semi trucks it's in the $3-500 range. Probably less for our smaller DPFs.

Successfully gutting a DPF depends on the particular tractor's programming. There are usually pressure sensors on the input and output side of the DPF to detect when it needs a regen. If it's programmed to sense that there's no pressure drop between them meaning that the honeycomb's been removed, then you may end up needing to buy a new DPF or having to figure out a way to trick the ECU. On Bransons the only computer is a "data recorder" that monitors the DPF pressure and temp. The tractor will run fine with it unplugged.

 

[ericm979]

This might sound a bit dumb, but most agree that breathing in diesel fumes, weather they have been through a DPF or other process, is not best for our lungs. But many tractors have their exhaust pipe right in front of the driver. This means that whilst travelling into the wind the driver is breathing in the exhaust fumes. Many have cabs, OK but still the cab is in the `fume cloud`. This leads to a question of, `would it not be better to move the exhaust pipe to somewhere else.` and `does the pipe have to be where it is or is just traditional, because that's where our fore fathers put them`

That's a good thought. Old tractors have their exhausts running straight up in a stack. I think the idea was to get the exhaust up above the operator. Having the exhaust low and facing forward is probably mostly for a sleeker look.

On my old Kubota b7100 the exhaust could be mounted to go up as a stack or forwards like most current CUTs. It worked, sort of- I didn't breathe too many fumes when mowing. But when changing implements in the barn or running the chipper with the wind coming from the front of the tractor, yuck. Some people have run a tailpipe out the back of the tractor but that's not going to be an improvement when running the chipper or mowing backwards.

 

[jeff9366]

Having the exhaust low and facing forward is probably mostly for a sleeker look.

More so compact tractors can enter a residential garage with an 84" header and work under tree branches in landscaping applications.

 

[prof fate]

Kioti dealer told me (2018 ck3510) keep revs at 1800-2000 min, and run it to operating temp. Less revs or lots of cold use (short run times) will increase the regen frequency.

Filter should last 3000 hours, costs about $300 to replace (didn't say clean).

Mine regens every 35-40 hours. Now that winter is here we'll see if that changes - much longer warm up times, less use overall, less time on it each operating session.

At work we run 2017 and 2019 IC school buses. Lots of slow. stop n go and idling. About 15% of them have had pretty serious DPF issues...IC claims bad sensors, and now that we've had some nearly 2 years the issues are less than they were - bus would go into a limp mode, limit rpm and speed to about 15mph...sucked to be driving and have it go into limp mode. A new filter is $900 on these machines.

 

[JimR]

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稚 know it. If it wasn稚 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稚 want to tempt fate so just let it do it痴 thing

My tractor in regen mode cranks up to 2600 for about 15-20 minutes. There is no way you can miss that happening. The first time it happened it threw me for a loop. I just stopped and watched it do its thing. recently I did do a few manual regens to try and solve a problem that I was having with low RPM's limp mode that turned out to be a bad hand lever controller. Had I learned all the controls on my tractor I could have easily used the linked pedal switch to see that the problem was the hand controller.

 

[Paystar]

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​

Well, luckily for the auto makers they grossly over charge for the junk they are selling us so it was affordable for them. LOL

 

[ning]

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

I don't think the Euro's been upside-down to the dollar in years (2002); you probably meant €27B = $30.76B.

 

[jeff9366]

YOOPER DAVE​

Tier IV Emissions Confusion​

Are new tractors with <25hp Tier IV emission exempt ?

The demarcation is 19 kW engine power output = 25.4794 horsepower.

While Tier IV exempt, tractors with <25.4794 horsepower comply with relatively loose Tier II emission requirements.



Some mfrs note no pollution filter is needed, but tier 4 compliant.

Most manufactures can meet Tier IV requirements without a Diesel Particulate Fillter up to about 27 horsepower via engine design and injection timing.

(Diesel Off-road emission standards are uniform in developed world.)

Then there is a horsepower gap.

Beginning about thirty-three horsepower most tractors have Diesel Particulate Filters.
If there is no DPF there is an alternative incendiary technology to burn off very fine particulates (soot). Sometimes exhaust heat is elevated all the time, sometimes periodically.
Diesel particulates must be burned. THERE IS NO FREE LUNCH.



Consider DPF and alternative soot burning exhaust technology as a sophisticated muffler.
When pondering a tractor purchase consider muffler technology last.

When considering a tractor purchase, bare tractor weight first, tractor horsepower second and (narrowly) rear wheel ballast third.

Tire wear and tire replacement will cause as many headaches and more expense than DPF for most long term compact tractor owners who can comprehend their Operator's Manual.

 

[jeff9366]

I wonder what would happen if the DPF was replaced with a straight pipe ?
Not that I have any intention of doing so, just curious.

DPF is connected to exhaust manifold in lieu of a muffler. If you replace DPF with a straight pipe your tractor will be ungodly loud.

 

[Threepoint]

My tractor in regen mode cranks up to 2600 for about 15-20 minutes. There is no way you can miss that happening. [snip]

Jim, with my NX, when I'm in medium range pulling a 7-ft box blade filled with wet crusher run, I'm at that rpm for an hour at a time. I think I could easily miss a regen if one were to happen. But, then, working the tractor that hard keeps the DPF pretty clean to begin with.

 

[CMV]

If I'm already at ~2k or higher RPM, it doesn't ramp up engine rpm to regen. Bush hogging at 540 PTO or tilling at a little less, tractor won't just run up to WOT to regen. It just does its thing and the smell or dash light is only way to know. I've never initiated a manual regen, but as far as the tractor doing them on its own, it doesn't increase engine rpm. Maybe if it decided to start one while the machine was sitting at a low idle or something it would?

I did notice that sometime after the 2nd regen, I get that "burning paint smell" in the exhaust all the time. Not as strong as when its actually doing a regen, but there all the time. Prior to that I only got that smell when it was in regen cycle. Is that normal? If I had to try to describe it, say on a scale of 1-10, 1 is normal exhaust smell with none of that "burning paint" (best I can describe what it smells like in regen), and 10 is in the middle of a regen with that smell very strong, for first ~80hrs or so exhaust smelled like "1" on that scale when not in regen. Since then, it's probably around a 3-4 on that scale when not in regen.

 

[RjCorazza]

My machine will not increase rpms during automatic regens. If the rpms are too low, an increase rpm light will come on requiring the operator to raise rpm. If regen requirements are not met, it gets increasingly complicated, and I believe at some point the computer takes over the throttle.
The regen stage chart from Kubota is very confusing (at least for me), and given that the last stage is auto shut down and call for service, I don’t push it.

 

[jeff9366]

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 normal 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.

R E V I S I O N​

Diesel Particulate Filter (DPF) captures exhaust particulates (soot) in a ceramic matrix. If engine is not operated sufficiently hot to incinerate exhaust particulates continuously, diesel soot accumulates in the matrix. Burning off accumulated DPF soot during active operation or parked is called REGENERATION.

Once heavy soot accumulates in DPF the tractor forces soot incineration through static PARKED REGENERATION. During Parked Regeneration engine speed increases to about 2,200 rpm, which heats DPF sufficiently to burn accumulated soot. Soot incineration requires about sixteen minutes once DPF reaches incineration temperature.

Beginning about thirty-three horsepower most tractors have Diesel Particulate Filters.
If there is no DPF there is an alternative incendiary technology to burn off very fine particulates (soot). Sometimes exhaust heat is elevated all the time, sometimes periodically.

Diesel particulates must be burned. THERE IS NO FREE LUNCH.​

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



Regeneration is an infrequent event for my Kubota three cylinder engine.
Generally once every sixty engine hours. (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 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]

A N O T H E R ~ R E V I S I O N​

Beginning about thirty-three horsepower most tractors have Diesel Particulate Filters.
If not DPF, the less used alternative emission technology is Diesel Oxidation Catalyst (DOC).
Both the DPF and the DOC are honeycomb ceramic filters.
The DOC forces engine exhaust over a honeycomb ceramic structure coated with platinum, palladium, and rhodium. These catalysts oxidize carbon monoxide and hydrocarbons into carbon dioxide and water at hot exhaust temperature.


Diesel Particulate Filter (DPF) captures exhaust particulates (soot) in a ceramic matrix. If engine is not operated sufficiently hot to incinerate exhaust particulates continuously, diesel soot accumulates in the matrix. Burning off accumulated DPF soot during active operation or parked is called REGENERATION.

Parked Regeneration is a process on diesel engines with diesel particulate filters (DPF) that temporarily changes the operating settings of the engine to generate extra-high temperatures in the DPF to combust and consume engine exhaust products (particulates/soot) that accumulate in the DPF during normal engine operation.

Soot conversion to ash requires about sixteen minutes once DPF reaches incineration temperature (500 deg F.) in warm Florida. Colder temperatures and higher altitude increase soot accumulation.

Forty percent of my Kubota regenerations occur during operation at high-throttle, sixty percent parked. Your tractor operation probably varies from mine.

DPF or DOC, your Tier IV engine has a ceramic-matrix, particulate-eliminator in the exhaust stream.
THERE IS NO FREE LUNCH.​

Regeneration is an infrequent event for my Kubota three cylinder engine.
Generally once every sixty engine hours. (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 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.

Tire wear and tire replacement will cause as many headaches and more expense than DPF for most long term compact tractor owners who read and comprehend their Operator's Manual.

 

[jeff9366]

Beginning about thirty-three horsepower most tractors have Diesel Particulate Filters (DPF).
If not DPF, the less used alternative emission technology is Diesel Oxidation Catalyst (DOC).
Both the DPF and the DOC are honeycomb ceramic filters.
The DOC forces engine exhaust over a honeycomb ceramic structure coated with platinum, palladium, and rhodium catalysts. These catalysts oxidize carbon monoxide and hydrocarbons into carbon dioxide and water at hot exhaust temperature.


There is no catalyst associated with a Diesel Particulate Filter. A DPF is a ceramic matrix which accumulates particulates/soot at temperatures below soot ignition temperature. During regeneration, when DPF achieves and maintains at least 500 degrees Fahrenheit, the temperature of a hot kitchen oven, accumulated soot incinerates during a few minutes.


Operator Manuals for DPF equipped compact tractors do a poor job of explaining DPFs and a poor job of explaining regeneration cycles. For instance, two manuals i have viewed do not inform that soot accumulates faster during low weather temperatures, none inform time required for DPF to attain 500 degrees fahrenheit, the ignition temperature for diesel soot and none address faster soot accumulation at higher altitudes. It seems to me a DPF temperature readout on electronic instrument panels would address many DPF complaints, as would more descriptive technical writing.


As off-road diesel engines increase in displacement and horsepower emission treatment becomes increasingly complex. DPFs as a final particulate treatment are primarily associated with diesel engines <75-horespower.


Keep in mind emission standards for over-the-road diesel engined vehicles are much tighter than emission standards for off-road engines AT THIS TIME.

 

[finn1]

Work we did several years ago at an engine rom shows that biodiesel will increase passive regeneration, increasing the run time between active or forced regenerations.

There were several papers generated at the time supporting this. I’m not sure why the bio industry never picked op on this.

The dyno and field test results at the time were quite consistent.

 

[ning]

During regeneration, when DPF achieves and maintains at least 500 degrees Fahrenheit, the temperature of a hot kitchen oven, accumulated soot incinerates during a few minutes.

My reading indicates that the incineration temperature is more like 600 degrees C - centigrade/Celsius - not Fahrenheit. This puts it more like 1100F, which is far outside your typical kitchen oven's range.

Under heavy load diesel truck EGT's will reach this temperature, which allows for passive regeneration; the regen cycle is required because typically engines aren't run that hot so soot does accumulate.

 

[finn1]

My reading indicates that the incineration temperature is more like 600 degrees C - centigrade/Celsius - not Fahrenheit. This puts it more like 1100F, which is far outside your typical kitchen oven's range.

Under heavy load diesel truck EGT's will reach this temperature, which allows for passive regeneration; the regen cycle is required because typically engines aren't run that hot so soot does accumulate.

High temperatures certainly are an element of active regeneration, but much of the passive regeneration is a chemical, rather than thermal, reaction, involving NO2 to NO ratios, if I remember correctly.

It’s been a long time, so the details are fuzzy.

 

[ning]

High temperatures certainly are an element of active regeneration, but much of the passive regeneration is a chemical, rather than thermal, reaction, involving NO2 to NO ratios, if I remember correctly.

It’s been a long time, so the details are fuzzy.

I didn't mean to say that this is how passively regenerating DPF's work, but there is soot cook-off which occurs when the EGT is high enough, but typically exhaust isn't hot enough, which causes the soot to accumulate.

 

[jeff9366]

Tier IV emission controls and DPFs began to phase in ten years ago. Old news in 2019.

Consensus is DPF problems are 90% caused by operators who do not carefully read regeneration procedures in Operator's Manual or refuse to follow the procedures. Many small property users regenerate just once per year. This creates regeneration procedure uncertainty in itself. (Regeneraton occurs every ~~60 engine hours. Non-commercial users average 80 engine hours per year.)

Operator Manuals for DPF equipped compact tractors do a poor job of explaining DPFs and a poor job of explaining regeneration cycles. Most manuals do not inform that filter soot accumulates faster during low weather temperatures, none inform time required for DPF to attain 1,100 degrees Fahrenheit, the ignition temperature for diesel soot and none address faster soot accumulation at higher altitudes. It seems to me a DPF temperature readout on electronic instrument panels would address many DPF complaints, as would more descriptive technical writing.



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.

Tire wear and tire replacement will cause as many headaches and more expense than DPF for most long term compact tractor owners who read and comprehend their Operator's Manual.