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spot smoke

donaldmc Member Posts: 35
I've been servicing a few dozen oil fired boilers in the past few years, some old as converted coal boilers others as new as this year.
On the burners on some of the older units I have trouble getting the spot smoke as clean as I'd like it. I can reduce the smoke if I adjust the air to the burner but I think I'm just diluting the problem, as well as skewing the combustion gases. Anyone have any insight on the best way to address the "dirty burn" on some of these older units.



  • lchmb
    lchmb Member Posts: 2,997
    some older units were set up to run with a trace of smoke. It depends what you've got...Thats why most have been retired..
  • Steamhead
    Steamhead Member Posts: 16,885
    If these are "flame-retention" burners as pretty much everything has been since about 1980, they should run with zero smoke and at least 10% CO2. Tell us what model burners they are and what they're installed in.
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
  • STEVEusaPA
    STEVEusaPA Member Posts: 6,505
    If these are old coal-converted, you may need an 'old' guy who knows how to match the nozzle and angle with the chamber. My father was able to put fire bricks in them and chamber kits, to avoid the eddy currents, but at this point, I think it may be easier to spend a little time with the smoke gun, and do a nozzle substitution test, maybe even changing the end cone.
    Start with steady state proper draft, and go from there

    There was an error rendering this rich post.

  • 776v63
    776v63 Member Posts: 61
    Delavan manual may be helpful for nozzle selection.

    https://www.google.com/url?sa=t&source=web&cd=2&rct=j&q=delavan nozzles&ved=0ahUKEwjex7-OjuvJAhUJWCYKHXhfAf8QFghAMAE&url=http://www.delavaninc.com/pdf/total_look.pdf&usg=AFQjCNHQPUu9WmuCSL2vcnyHcGE858LXVg&sig2=PBhoqSgbkY2QTqdZHRLNpQ

    May not be as useful as an "old guy", but as a young guy with limited access to such experience, I've become pretty good at Google searching product manuals. ;)
  • donaldmc
    donaldmc Member Posts: 35
    Thanks for the comments. The boiler giving me the most trouble is a 1913 crane gravity system. I put a Lynn quickie chamber in 2-3 years ago and adjusted the Carlin burner-3450 motor (abut 20 years old) as suggested at that time. Every time I service it, I'm bothered by the spot smoke with a reading of 2. The only thing I haven't done is reduce the flue pipe size which is the original 14" from it's coal burning days. The burners running a 1.5 60b nozzle at 130 lb pressure. CO2 is at 10.5; any higher and the smoke gets worse. I'd like to reduce the flue to an 8 or 10" but I'm not sure if it would help. A newer burner might help but the home owner would not like the expense.
  • Bob Bona_4
    Bob Bona_4 Member Posts: 2,083
    You are never going to see 10 percent on that relic. Too much leakage. Get the smoke down to 0, barely a trace, and the CO2 is what it is. 8 percent wouldn't be a bad range.

    Funny how homeowners see new equipment as an expense but overlook how much it's costing them everyday to run these obsolete pigs.
  • donaldmc
    donaldmc Member Posts: 35
    Thanks for the feed back. In regard to the 1913 Crane, the Delavan manual gave me the idea of a 45 degree nozzle (was 60) due to the shape of the chamber. After readjusting the burner the smoke disappeared and it had a 8.5 CO2, and thanks to Bob Bona I'm declaring it as good as the old boilers can get!
    Thanks guys!