NonDpf vs Dpf

[DirtCrawler]

Other than one has a filter and one doesnt. Whats the difference and the pros/cons of a NonDpf engine vs a Dpf engine.
for instance Bobcat (nondpf) vs Cat (dpf).
They both still need to regen right?

 

[jav]

Other than one has a filter and one doesnt. Whats the difference and the pros/cons of a NonDpf engine vs a Dpf engine.
for instance Bobcat (nondpf) vs Cat (dpf).
They both still need to regen right?

I'm not 100% up on equipment technology but I can tell you with cars- most clean diesels, will have a DPF. Some light duty cars only require the DPF and no Urea additive while others require both.


Regen is only required if DPF equiped - to convert (burn) trapped soot to ash, which particulate wise, is much smaller than soot (but remains trapped). DPF also requires use of low ash oil, periodic cleaning or replacing. DPF are NOT pass through devices- they are collection traps that accumulate particles.

My understanding is that BOBCAT tier 4 were only NON-DPF in lower Hp engines (upto around 75 hp?). Anything larger still had DPF as far as I knew.

 

[durallymax]

I haven't really found something that explained Doosans approach very well yet. I do know it is non-dpf.

DPF's need to regen, nothing else does. As jav explained, it simply reduces the soot to just the ash by heating the DPF up. This can happen passively with no added fuel if you are working the machine hard, actively with added fuel as you are working with the machine, or parked with added fuel if you ignore the DPF cleaning for too long.

Obviously its nicer to not have to deal with one at all, but like everything its only one factor to influence a purchase decision. IMO its one thats pretty low on the list too. There are also sometimes tradeoffs on how the OEM gets their engine to meet standards. They may use new tech that has some bugs to work out, or some alternative system with its own downsides. All of the new equipment has a lot of emissions controls, they vary in their approaches and designs but I wouldn't say one excels over the other enough to say buy brand a over brand b just because of their emissions system.

DPF's have been out for quite awhile now and while there were a lot of bugs originally, they have gotten a lot better.

On the D series Cats, they will flash an indicator when the DPF needs a forced regen. When that indicator comes on, turn the hand throttle into the green area and keep working. The machine will also start a regen on its own if it sits idle for a minute or two. It will rev up and start performing a regen until you want to move it again. If you ignore the regen and do not increase the rev's or let it do a parked regen it will go into the next stage after awhile which requires you to park the machine for a regen.

At some point the DPF will be full and need to be replaced or cleaned off the machine. Cat says the DPF should last 3,000-5,000hrs in these machines. I do not know what Cat has for a system right now. With many of these engines they simply have a core system setup where the dealer will replace your filter cartridge with a cleaned one and they will keep yours to clean and put in the next guys machine. This service costs a couple hundred dollars usually. It is an extra expense and inconvenience, but with the long service interval you wont be doing it often.

 

[Military Grunt]

I found a really good chart of what many manufacturers are doing. I know Bobcat, like you said, has DPF in their engines above 74hp, but according to the flow chart they won't. Either way, this is a good chart from the magazine Diesel Progress to reference.

http://www.dpna-digital.com/dpna-sample/sample?pg=104#pg104

 

[durallymax]

I found a really good chart of what many manufacturers are doing. I know Bobcat, like you said, has DPF in their engines above 74hp, but according to the flow chart they won't. Either way, this is a good chart from the magazine Diesel Progress to reference.

http://www.dpna-digital.com/dpna-sample/sample?pg=104#pg104

Nice chart.

Bobcat currently has a DPF on the larger machines but those are not Tier 4 Final and IIRC they are still a 3.8 Kubota. The Tier 4 Final Doosan will have EGR and a DOC like the smaller ones but will also have SCR. The larger Cat's with the 3.8 Kubota will also recieve SCR in addition to the DPF and EGR.

 

[KSSS]

Why does Kubota AKA Cat find it necessary to use SCR+DPF+EGR? That is a serious negative in my view.

 

[DirtCrawler]

Talking to the sales guys the way I understood it was that
Cats DPF, like Durallymax said, will need to be cleaned at approx 3,000 hrs.
Cost was around 300.00 to clean the filter.
Bobcat in a S590 (66hp), like jav said is non-dpf, the sales guy added something along the line of that the exhaust is different in those units where exhaust burns hotter all the time which does away with the dpf filter.
And since its burning hotter provides higher combustion pressure for more torque… blah blah blah .. thereby there is no regen period like on a cat, and having to wait for a regen.
Also he stated that some machines when they do a parked regen, you may have to wait a while before until its done. Which I took as you wouldn’t be able to use the machine in a parked regen.

On the Cat the sales guy said as long as you operate the unit with the throttle in the green area that you will not have to worry about any regen. And pretty much what Durallymax said about the regen process.

My concerns are.
Bobcat – if its burning hotter all the time, seems like it would have to be consuming more fuel to do it. + alot more engine compartment heat.
But then I could see where if theres no regen going on, its probably not robbing power from the engine.
The exhaust chamber, if something should happen is probably expensive to replace.

Cat – If it goes into regen, Am I going to be losing engine HP or torque during the process, which bobcat I guess I wouldn’t.
But then if the Cat goes into a regen I would be using more fuel for the regen anyway correct.


The other thing is
Bobcat does not state anywhere, at least that ive been able to find
Engine displacement.
Peak torque at a certain rpm.
Breakout force.
I find this odd. Everyone else does.

 

[KSSS]

I was going to buy a 2014 CASE SV300 this Fall. However the 2015 version will be SCR with no DPF. I opted to wait for that so as not to have worry about the DPF. I would rather deal with DEF than deal with DPF.

Certain OEMs make some numbers very difficult to find. CAT refused to publish any torque figures until they started using the Kubota engines. Reason being I assume is because they were very low compared to everyone else (around 218 on their larger machines).

 

[Z2898]

Currently studying Tier 4 interim versus Tier 4 final and hopefully can add some factual info to this discussion.

The goal of Tier 4 interim was to decrease PM (particulate matter). PM is in two forms, carbon particles from the combustion process and ash which is part of the fuel after combustion. Soot (carbon) and ash are 2 different things. Carbon is the result of incomplete combustion and ash is a by-product of the fuel. T4I was equipped with a DPF to filter the carbon (soot) and ash. After a period of time the machine was required to go into a regeneration of the DPF which means exhaust temps had to be elevated to convert the carbon into other properties. (ARD systems added) This is fine but did not remove ash in the DPF. Over time (5000 hrs as an example) the DPF required removal and cleaning of the ash content from the DPF had to take place. Tier 4 interim did not reduce Nitrates of Oxide significantly (NOX). NOX is a result of combustion at too high of a temperature. (We went through this in the 1980s in the gas engine world)

Tier 4 final in a sense is very different than T4 interim. Tier 4 final now goes after reducing NOX. Its kind of strange because T4 final engines use advanced timing strategies to increase NOX first (high combustion temps = less soot). Also this means that the exhaust temps are higher which results in more passive (all the time) regen is able to take place. When we have increased exhaust temps from the combustion process we no longer require as much active (operator induced) rengen (ARD systems) to elevate the exhaust temps to regen the DPF. When combustion temps go back up (T4 final) more NOX is produced. In order to treat the NOX an SCR (selective catalytic reduction) system has been added. SCR is a way to treat exhaust to convert NOX to other things such as Nitrogen (N2). SCR systems use DEF (Diesel Exhaust Fluid) which is 67.5% water and 32.5% Urea. Through the process the urea is sprayed into the exhaust stream and helps reduce NOX emissions up to 93%. T4 final also in a lot of engines will use EGR (exhaust gas recirculation). When inert exhaust gas that has been cooled through an NRS (NOX Reduction System) and introduced to the intake air, the combustion temps are lowered, which in effect reduce NOX. This strategy helps to reduce NOX through the combustion process. Most engines, because the combustion temps are increased, produce less soot, therefore regen can take place all of the time (they call it passive regeneration). Active or induced regen is required less often.

There are many factors at play with T4 final. All strategies are required to reduce/eliminate emission based on Tier 4 requirements mandated by the EPA. Hopefully some of this will help you. If you have specific questions I may be able to help.

Z

 

[durallymax]

And since its burning hotter provides higher combustion pressure for more torque… blah blah blah .. thereby there is no regen period like on a cat, and having to wait for a regen.
Also he stated that some machines when they do a parked regen, you may have to wait a while before until its done. Which I took as you wouldn’t be able to use the machine in a parked regen.

Cat – If it goes into regen, Am I going to be losing engine HP or torque during the process, which bobcat I guess I wouldn’t.
But then if the Cat goes into a regen I would be using more fuel for the regen anyway correct.

You as the operator are the one in control of a parked regen. The salesman against this concept blow it out of proportion. The only time you have to do a parked regen is if you, the operator, ignores the ECM's request to do a regen while operating, meaning increasing the RPMs to half throttle and continuing to work. It should not interfere with your work, you can reduce the RPM's when needed then resume half throttle or more to continue the regen. Only when you ignore the indicator for a long period of time will you be required to do a parked regen. This is with most brands.

An active regen will not rob any power, it will use more fuel.

 

[Military Grunt]

Talking to the sales guys the way I understood it was that
Cats DPF, like Durallymax said, will need to be cleaned at approx 3,000 hrs.
Cost was around 300.00 to clean the filter.

Yeah everything depends on where you live though. It may be $300 where you are and $600 somewhere else. I read an article the other day that said they can range from $200-$800 and you are supposed to get them cleaned somewhere that's certified. If you try and do it yourself, it'll end up costing thousands to fix. Also, I know that guys in the colder areas of the country were having DPF issues in the winter. I guess they were letting the machines idle to warm or were letting them idle on the trailor while they went to the next area to move snow and it was causing issues with plugging or parked regens. I've heard it was frustrating, but this whole winter was frustrating I guess.

 

[Military Grunt]

My question is, why aren't they all going without DPF? Some do, some don't. If you can get by without it, why would you still produce an engine with it?

 

[KSSS]

My question is, why aren't they all going without DPF? Some do, some don't. If you can get by without it, why would you still produce an engine with it?

I would guess for whatever reason those that have a DPF cant get by without it. There certainly is no benefit to having it and DEF, just more complexity. Sometimes those filters cant be cleaned. I have heard of up to $1800 for a replacement. All that mess is what convinced me to wait for the DEF machines to roll out.

 

[Z2898]

My question is, why aren't they all going without DPF? Some do, some don't. If you can get by without it, why would you still produce an engine with it?

My understanding is this.

Very true that some engines can meet T4F emission standards without a DPF. There are many things that contribute to this but the easiest way to say it is these engines run clean. Piston design, injection pressures, fuel mapping, head design, injector design, block design and many other things that contribute to the cleanliness and the decrease of particulate matter. The only problem is these engines have a high NOX output (high combustion temps) that require after treatment with SCR and DEF fluid. I have also noticed that larger HP engines seem to need multiple solutions, DPF, SCR etc.

I also believe that as time goes on emission solutions will become less complicated and treatment systems will become more evolved.

Z

 

[Shimmy1]

I know this is a skid steer thread but I have some knowledge on the subject. My 2014 Case CX210C excavator has DPF. Re-gen takes place automatically about every 8 hrs. I've put just about 500 hrs on it and haven't had to do a manual re-gen yet. There is a gauge in the display that shows how full the filter is getting. Four blocks the fifth one it goes into re-gen. Machine needs to be at operating RPM so if it goes into re-gen and I need to stop I just make sure the auto idle/stop is turned off and let it do it's thing. In case anyone is wondering it is an Isuzu 4 cyl. 164 hp.

 

[Military Grunt]

I would guess for whatever reason those that have a DPF cant get by without it. There certainly is no benefit to having it and DEF, just more complexity. Sometimes those filters cant be cleaned. I have heard of up to $1800 for a replacement. All that mess is what convinced me to wait for the DEF machines to roll out.

I wouldn't wait if I were you, I am guessing that those machines will cost extra... Think about if. Def system, tank, lines, heaters, etc. I bet it'll cost you thousands to wait. i'd get an iT4 while you can if i were you.

 

[JCBiron]

I opted to wait for that so as not to have worry about the DPF. I would rather deal with DEF than deal with DPF.

Seconded!

 

[durallymax]

I was going to buy a 2014 CASE SV300 this Fall. However the 2015 version will be SCR with no DPF. I opted to wait for that so as not to have worry about the DPF. I would rather deal with DEF than deal with DPF.

I don't mind DEF one bit, go through a few hundred gallons a year now with the stuff we have running it. But I wouldn't say dealing with DEF is any better than a DPF. DPF you service off the machine every few thousand hours. Yes it will need to perform regens while you are operating, but it doesn't effect your operation. If you like to idle alot, the DPF will not be happy.

SCR has its share of downsides also. You need clean DEF, stored in the proper environment and will need to fill system often. Many machines are setup to make it at least one operating day or 1-2 tanks of fuel depending on how you operate it. The harder you run it, the more DEF it will use. DEF is mildly corrosive which can cause some issues, not often though. DEF will crystallize/freeze below 12* F. The systems are designed to deal with this, but they have had their share of issues the past couple winters. CNH in particular has had the most issues in the Ag sector. Then there are the components in the DEF system that seem to have high failure rates. NOX sensors, DEF injectors, Dosing modules, Heaters, sending units, etc etc. I don't like DPF's, but they only have one part to replace, the DPF. None of the DPF's on our farm have caused any issues, but the SCR systems have had their share of parts replaced. Thankfully under warranty as the price for those components makes the cost of a DPF look like ramen noodles.

I mentioned proper storage for DEF. There is a lot of confusion surrounding this topic. DEF does freeze, but freezing does usually harm it in any way. Heat will effect it and shorten its shelf life. DEF needs to be kept out of sunlight and preferably in cooler temperatures. Over 80* the shelf life really starts dropping. 86* constant will net a 2 year shelf life. Get over 100* and you are down to less than 6 months at best. At 32* it will last forever, 70* will go over 5 years. Its important to take this into consideration when buying. Bulk or IBC totes will be the best pricing (I pay $1.70 bulk delivered) but you need to be able to use it up before it will go bad. When it will go bad depends on how you store it and when it was produced to begin with. Your supplier should have a born on date or batch code for you to look this info up. It's best to store it in a shop and this works fine for some people, but for those who have to go out to the jobsite it can be a pain. It's best to store it in a closed system as well, sealed from the environment. Our system is from PIUSI. It was a little over $1,500. Some people will transfer from bulk to jugs to take with them. This can work, but since it is an open system there is always a risk of contamination. Generally the main issue from this method is plugged DEF filters.

 

[KSSS]

The DEF machine is costing me an additional 6% so I am told. So while it costing me more to buy, I still believe from the information that I can gather, I would rather go with DEF than DPF. Certainly DEF is not without its issues. I just think the engine will run better with aftertreatment than a filter that restricts the engine and is more sensitive to how it is run. As far as which will be more cost effective over the long haul? I don't know, but DPF is a dying technology. Eventually you will have a short range of years of machines that used that technology (tier4I only), it will get more expensive as the years go by, at least I think so. DEF is here to stay and it will get better. I will be on the learning curve of that, but I am very well taken care of.

 

[DirtCrawler]

https://www.heavyequipmentforums.com/showthread.php?46149-Kubota-or-Doosan-in-bobcat

doosan has been building engines for over 50 years.....

of the 2 i'd pick the non DPF doosan.
just because is non DPF.

on the kubota engines if you ignore or override passive regen warnings the engine will "detune" itself by as much as 75%

by that time theres nothing an owner or operator can do, except call out the dealer have have them do a parked/service regen.

https://www.heavyequipmentforums.com/showthread.php?43123-Pre-Purchase-Help

The Cat DPFs don't need to be cleaned at 1500hrs. My buddy sells them in Wisconsin and they have 242Ds in Dairies pushing 2500hrs and they have not had to be cleaned yet. The cleaning interval depends on the exhaust gas temps and how hard you work your machine when its running. I also have multiple buddies still selling Bobcats (I used to be a Bobcat salesman with them) and the new Tier IV Bobcats derate in cold weather until the engine is running hot enough. This is in right in their the OMM and the machine beeps at you when it derates. He said when it was cold this winter they had customers waiting up to an hour of running before the machine wouldn't derate anymore.

It derates because the exhaust gas temps are too low. Has nothing to do with oil at start-up. This is because their Tier IV machines do not have a DPF. Cat's machines have a DPF and don't rely on higher exhaust gas temps to burn off the particulate matter (PM) because the DPF stops the ash (PM).

Ok,
So NONDPF im assuming you have a cold weather problem where the exhaust temps cant keep up so it derates the engine. Correct?
and with the DPF im assuming you stand the chance of loosing 75% power (derate) if you ignore a regen.
So in either case your machine is derateing whether dpf or nondpf. Correct?
and the NONDPF wouldnt have to derate in the summer since its not cold, where the DPF is still gonna regen all year around. Correct?

On average how often does the cat have to do a regen. If im running the throttle in the green zone 95% of the time?

What happens at the end of the day, its 2am and I want to go home, and I just pulled the machine into the garage and it wants to regen. Can I just shut it off and go home or am I gonna have to let it do its thing.