the doser set up uses low pressure (just under 100 psi) so it's not that high tech. electric fuel pumps are capable of that kind of pressure so yes it's extra parts but I can't see them costing that much for a better system but I'm no engineer
21 years off the grid and counting
I'm sure the 'logic' behind DPF's is that the particulate matter is stored when at lower rpm's (in town) then the thing re-gens on the open road (out of town)
Trouble is the carbon and whatever else is still around us.
Here in the UK only a few of our power stations can burn WMO as most of them don't have efficient scrubbers to reduce emissions.
Apparantly as a result a lot of our WMO gets shipped to China where it is burnt in their power stations?
Diesel particulate filters remove certain small particles from the exhaust stream where they are then eventually burned and the ash from the burn remains in the DPF.
The particles trapped never make it into the atmosphere as they are burned up in the DPF and turned into ash which collects in the DPF.
Over time the DPF will fill with ash and will need to be cleaned out or replaced depending on design.
Some DPF's come close to removing 100% of the dangerous particulate matter from the exhaust.
Perhaps that is the what its supposed to do, however the huge clouds of blue and white smoke during a regen suggests otherwise.
If you have a look on the dieselstop forum you can see where a couple of people have received tickets due to the smoke coming from their trucks during a regen.
Or is the smoke supposed to be "healthier" then your standard diesel exhaust smoke?
As far as I can tell the DPF is a huge waste of fuel and efficiency that also creates maintenance issues, is that balanced out due to decreased pollution? I would bet not.
I would love to see a comprehensive study on this.
Yes, Diesel Particulate filters have been a problem. That is why I am staying right away from them.
No doubt there are a variety of reasons for this trouble including poor DPF design and people still using their diesel vehicle as a run around town vehicle.
Ideally, diesel vehicle would be driven in such a way that they always passively regenerated and never actually had to go through an active regenerate.
I guess people need to relearn how to use diesel vehicles. There are new rules to the game.
I live in a town that is a main truck route with hundreds, perhaps thousands of large semi's and Road Trains driving through each day. Many of them will have to stop at one of the traffic lights.
When these heavily laden trucks move off from the stoplight you rarely see any visible smoke, never mind the huge billowing black smoke clouds that used to be part of what diesel trucks did.
Even more pleasantly, there is no longer the acrid stench of burnt diesel that was just part and parcel of being near a road used by diesel vehicles.
I think they are doing something right
I am sure a bit of time google searching would provide you with the info you are looking for.
Agreed. I liken the DPF to having a swimming pool with a peeing area. Rather than letting the pollution out a little bit all over, it catches it and then lets it all go in 1 place at one time during the regen. That's all fine and good if the stretch of highway is out in the middle of nowhere, but just statistically it would be more likely to happen on a highway through the center of a major town.
In my opinion, the best way to reduce emissions, REAL total emissions over an entire tank of fuel, not the stupid instantaneous-emission that the test stations measure for, is to burn the absolute least volume of fuel necessary for a fixed distance. So anything that decreases the MPG is detrimental to emissions, even if it appears to help on the sniffer tester.
Its nice to hear that you see a positive effect where you live, that's a good thing!
While sitting here with my lobsters in the snowy Halifax airport waiting for my plane, I had some time to do some investigating. Though I cant find any studies comparing the effects of decreased mileage and maintenance compared to pollution on the overall environment, I did find a couple of studies that make a pretty compelling case that the DPF is a good thing for our health.
Listening to your testimony of the effects you noticed where you live and reading the above studies has pretty much convinced me that we need this DPF technology.
However this technology needs some better engineering so it can effectively cope with biodiesel as well as reduce the maintenance and fuel issues...
I guess we cant have our cake and it too eh!? At least not yet...
Yes, that's how I thought they worked too Ryan, though further investigation reveals that is not the case. Have a glance at the studies I linked to above and you will see what I mean. When they are working correctly they are removing carcinogens from the exhaust. The problem seems to be keeping them working properly and of course the complete snub to the few of us using biodiesel, but its pretty obvious why we wouldn't get any consideration when designing these things...
from what I'm reading it would seem that the particulates are the carcinogen and the nox is more related to smog. I found this though
and on SCR (DEF)
Selective catalytic reduction (SCR), using
urea as a reducing agent, has also been
installed on diesel-powered ve
hicles. SCR is capable of reducing NOx emissions from
75 to 90 percent while simultaneously reduci
ng HC emissions up to 80 percent and PM
emissions by 20 to 30 percent. SCR system
s are available on most Euro IV and V
compliant heavy-duty trucks in Europe.
SCR technology has been selected by several
engine manufacturers for meeting the upc
oming U.S. 2010 on-road regulations.
Numerous demonstration projects intended to
commercialize SCR systems for vehicles in
the U.S. are underway at this time.
21 years off the grid and counting
Central America and particularly Honduras have some of the highest diesel sulfur levels in the world. New diesel cars and pickups are common yet I haven't met anyone (including mechanics) here who has heard of a DPF system. I believe they aren't compatible with high sulfur fuel. So assuming the vehicles haven't been fitted and adjusted for a DPF regen system, wouldn't they be more compatible for running with biodiesel. I've been brewing and running B100 in my 2000 Mazda for about a decade and want to purchase a new diesel truck.
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