Talk:Diesel particulate filter

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Archives of Past Discussion[edit]

Archive 1

Very Impressive Technology[edit]

Our school just obtained a new fleet of school buses, powered by the Navistar MaxxForce diesel engines. After two months of regular service, the inside of each very large exhaust pipes is as clean as the day it was put together, that is, soot-free. I will add specifics regarding how this improvement was attained--sorry that I don't have it now. I did find out that this line of engines is using the very high pressure common rail injection system with up to five openings per each firing of a particular cylinder. User: HomeBuilding (talk) 01:48, 23 September 2010 (UTC)

Catalytic Converters - The Book[edit]

Since my body won't let me work any more, and I've now been out of the business for over two years, I'm going to write a book on Catalytic Converters. I'm one of the few people who isn't in the business who qualifies as an expert, understands the chemistry, the physics, and how engines work. Because I worked in the business for over ten years, I have names in my rolodex for people who work at every company, to help me fill in the blanks.

Besides, after seeing some of the stuff that has happened on this page over the years, well you folks need a reference that you can use that is reliable. I'm posting this here because I know what I think should be in the book, but I don't know what you think should be there. What questions would you like to see answered? Let me know on my talk page.

I am intending to include a section on Diesel Oxidation Catalysts and Diesel Particulate Filters. UrbanTerrorist (talk) 05:01, 22 September 2011 (UTC)

Fuel Economy. More clean up. Break down.[edit]

This is what the section looks like currently:

Fuel Economy

Particulate filters significantly* decrease fuel economy, which is why automobile and truck engine manufacturers have avoided the use of filter technology until now.[citation needed] Because an engine's carbon emissions are directly proportional to its fuel usage, an engine equipped with a diesel particulate filter may have up to twice the carbon emissions of an equivalent engine without a DPF.**[citation needed] Unlike the filtered particulate, carbon emissions (CO2) are considered greenhouse gasses which contribute to global climate change.

The motivation behind mandating DPF's in the USA was not to slow global warming, but instead to reduce visible smoke from exhaust gasses.***[citation needed] By the time laws limiting diesel particulate went into effect in 2007, diesel engine technology had advanced to the point that modern engines produced no visible smoke (without the use of a DPF) except when cold or heavily loaded.[citation needed]

  • I support removing the word significantly all together. It doesn't hurt MPG that much, I've deleted them before and noticed only minor improvements in fuel economy.
    • Because an engine's carbon emissions are directly proportional to its fuel usage, an engine equipped with a diesel particulate filter may have up to twice the carbon emissions of an equivalent engine without a DPF. May have if it is not functioning correctly. It increases carbon emissions buy 50% maybe a stretch.
      • That was only part of their motivation.
        • Most direct injection engines got the smoke thing under control.

The wording seems a bit bias. But the IP user intentions are good.--Dana60Cummins (talk) 19:55, 4 October 2011 (UTC)

After reading it, and checking all of the citations, I've deleted the Fuel Economy section. One citation was speculative, i.e. an article published before the law came into force. There was no documentation that proved any damage to fuel economy. There were links that were advertisements, Wikipedia is not a forum for advertising. There were links that were not properly explained, like one which tried to imply that "visible smoke" was the reason for the legislation, where anyone who had bothered to actually read the Federal Register (I did) would know that particulate has a wide range of health impacts, including being a carcinogen. The IP user intentions might have been good, but the IP user had no understanding of the subject. Anyone who attempts to put the Fuel Economy sub-section back into the article had better do their homework. Remember, I designed a couple of Diesel Particulate Filter systems. I know the technology. I know engines. Do your homework, do your research, get it right, and I'll happily help you round it out. Put up something like the piece of junk that I deleted, and I'll delete it again. Our job is to provide users with the best damned encyclopedia that we can, and that means that we have to be accurate. UrbanTerrorist (talk) 19:46, 5 October 2011 (UTC)

Discussion Boards for people with questions[edit]

We keep getting people here asking questions about filters which the article isn't aimed at answering. I think that we need to add or at least have a place to send people. When I was still working in the industry, the best place I knew of was the Dieselnet Forums. UrbanTerrorist (talk) 20:36, 16 October 2011 (UTC)

We will not be adding a discussion board for people with questions about the subject of articles, because that is beyond the remit of the Wikipedia project. I ask you again to mind that article talk pages are not forums for discussion of the topic of the article. They are for discussion about the article only. Thank you (again). —Scheinwerfermann T·C23:30, 16 October 2011 (UTC)
I would ask you to read what I wrote before replying. UrbanTerrorist (talk) 03:45, 17 October 2011 (UTC)
I did. My comment was in response to what you wrote. This just plain flatly is not the place for the sort of discussion you have in mind. Not even a little bit. —Scheinwerfermann T·C05:02, 17 October 2011 (UTC)
What are you talking about? UrbanTerrorist (talk) 18:53, 17 October 2011 (UTC)

This is not a place for a forum. Nor is it a place to direct questions either. --Dana60Cummins (talk)

And I didn't mean to make this a forum, and I didn't mean to make it a place to ask direct questions either. What I did mean was to give people a place to go, so that we could get them out of our hair. UrbanTerrorist (talk) 01:00, 19 October 2011 (UTC)

DPF regeneration[edit]

John Nevard, it's very clear you are not a fan of DPFs. It's your right to hold that opinion, of course, but it is not appropriate for you to weave it into articles on Wikipedia. I would really like to avoid having to report you for vandalism, but your persistent and willful introduction of assertions not supported by the refs you provide will eventually force my hand. Most recently, you have repeatedly ([1] [2] [3]) inserted the assertion According to the UK's Automobile Association, DPF systems may not regenerate properly even on cars driven mostly on motorways. You have supported this assertion by reference to this page. However, that page does not support your assertion. The closest it comes is If you ignore the warning light and keep driving in a relatively slow, stop/start pattern soot loading will continue to build up until around 75% when you can expect to see other dashboard warning lights come on too. At this point driving at speed alone will not be enough and you will have to take the car to a dealer for regeneration. That supports my edit of your assertion, to wit, If the driver ignores the warning light and waits too long to operate the vehicle above 40 mph (64 km/h), the DPF may not regenerate properly. Please try to contribute in a more coöperative, less combative manner. Thanks. —Scheinwerfermann T·C03:30, 26 October 2011 (UTC)

You seem to have an aversion to actually reading the source. Why not try doing that? I was even kind enough to quote it in the edit you just decided to revert. Nice work. Nevard (talk) 03:32, 26 October 2011 (UTC)
I back Scheinwerfermann on this. I used to design these things, Yes, if you are an idiot, you can have problems. If you continue driving the car after the ADD MOTOR OIL LIGHT has come on, you expect problems. If you don't you are probably a good candidate for a Darwin Award. UrbanTerrorist (talk) 03:38, 30 October 2011 (UTC)
Thanks, UrbanTerrorist, and I agree with you that stupidity merits its consequences, but this what we agree on isn't the point under discussion. What's under discussion is this particular bit of the article. The text Mr. Nevard repeatedly inserted was evidence of DPF systems failing to regenerate even on cars used mainly on motorways. The trouble is that this quote does not adequately or accurately summarise the content of the document. As taken out of context by Mr. Nevard, it implies DPFs clog up even under driving conditions supposedly sufficient to ensure their regeneration. The document goes right directly on from there to say on cars with a very high sixth gear the engine revs may be too low to generate sufficient exhaust temperature for regeneration. Occasional harder driving in lower gears should be sufficient to burn off the soot in such cases. That context changes the import of the "even on cars used mainly on motorways" quote quite a bit. The present text in this article, supported by this reference, reads If the driver ignores the warning light and waits too long to operate the vehicle above 40 miles per hour (64 km/h), the DPF may not regenerate properly, and continued operation past that point may spoil the DPF completely so it must be replaced. This seems to me a more accurate capsule summary of the content of the document. It also looks a great deal less like selectively-trimmed text inserted in a manner giving every appearance of being calculated to push a point of view against the use of DPFs. —Scheinwerfermann T·C04:59, 30 October 2011 (UTC)
This is where I sound paranoid. Have you perhaps noticed a pattern? Here and on the Catalytic Converter page we get addition after addition about the dangers, lack or reliability, lack of performance, etc. Interesting, isn't it? UrbanTerrorist (talk) 03:45, 1 November 2011 (UTC)

──────────────────────────────────────────────────────────────────────────────────────────────────── You're not paranoid, you're observant. It also happens on Exhaust gas recirculation. Astounding though it be, we still have ignorant morons babbling about how emission controls are stupid, unnecessary, advocated only by poopooheads, etc. —Scheinwerfermann T·C04:25, 1 November 2011 (UTC)

US centred[edit]

I'm no expert on this matter, so can't really edit it. However, one thing I have noticed is that the history section is reasonably US centred. For example, I've found a British bill regulating all hydrocarbon fuels from 1973. If someone were to edit this section to include worldwide history on the matter it'd definitely improve the article. (talk) 18:51, 29 January 2012 (UTC)

Increase in NO2/NOx ratio[edit]

I think it would be useful to include some information on the impact of Diesel particulate filters on the NO2/NOx ratio in the emissions. This has potentially quite an important effect on urban NO2 concentrations e.g. this article. There is an interesting policy challenge here - clearly both PM and NO2 are important pollutants. I would do it myself but I am tied up with rewriting aerosol at the moment.--NHSavage (talk) 16:32, 28 July 2012 (UTC)

Removed sketchy external link, here for discussion.[edit]

Removed sketchy link:

Believed sketchy for reasons shown here (scam)

"oxidize the accumulated ash"[edit]

How is that chemically possible to oxidize ash?