oil burners blackened flue

[sugarstone]

Any suggestions to quickly clean underside of flue? I can only jack up my hood 3-4inches, therefor the flue only raised up same.

I've been having issues with my two Carlin 601 burners on my 5x16 D&G/converted woodfired arch. It worked fine before.
Been struggling to fix the problem of the burners not completing the combustion of the oil. This has led to my flue pan becoming very black...front pans as well, but I've been cleaning them after each boil.
I don't think the combustion problem is fixed but now most of the heat is going up the stack. Stack temp was around 600-700, now it is pushing over 1000.
I believe this is causing the evaporator to not draw-off syrup.

I wouldn't be stressing too much but we have over 2000gal of sap in storage (maxed out) and now it looks like we will be getting a few more runs in next few days.

[Thad Blaisdell]

Are you adjusting your air?

[highroadsyrup]

Thad is on the right track. Your not getting complete combustion. If the air adjustment doesnt fix the problem check your nozzle & filters next. Another area to check would be the end cone area, if that is carboned up that will screw up your fire as well. Make sure the power is off before taking things apart :o.There is a product called a soot stick that may help once you get the burner fixed.

[Kev]

you might find that the problem originates with your fuel.
This year when I ordered heating oil. I got #2 high sulfer farm fuel....(my supplier said that is all they could get) it burns much dirtier and has less BTU's per gallon. It definitely needed an air adjustment to the burner

[sugarstone]

we adjusted the drafts to get more air. That took the smoke away but not the buildup underneath.
I had 8gal/hr, 60degree nozzles and tried 45s. By doing that I think I took the oil/soot buildup and put everything back farther and now have buildup under the flue so bad that it has dropped the flue boiling temps and as a result has messed up the whole drawoff concept.
Another producer enlightened me to the black flu pan=heat going no where but up stack problem.
I boiled last night trying to fix the drawing off problem and also putting the 60s back in but didn't work. I also cranked the air up more on the one problem burner. I will be taking the pans off to see if that made any dif.
I hope to be able to crawl under my flue to clean it as I really would like to avoid draining/jacking up my riggin. won't be fun whatever I do.
Thanks all for the tips.
..time to get black.

[Thad Blaisdell]

Run the flame with the pans off.... that will let you adjust the air better. just turn on for a couple of seconds to see what it looks like then adjust.

[highroadsyrup]

If you can get inside to brush it that will help, wear some breathing protection. If memory serves me .... 1/16" of soot is equal to an inch of insulation, not good for boiling ZAP :(

[Brian]

Get rid of the carlin 601 and get 701 -702 or 801 because the two stage burner will automatically adjust the air. The low fire gets things rolling and the high fire keeps the silt off the pans(unburned fuel) If the draft is not right or heat is not hot enough, condensation will form on the bottom of the pans causing the black silt to build up on the pans.

[Haynes Forest Products]

Kev are you sure about the BTUs of #2

[sugarstone]

found the pump pressure of one of the pumps was low, so we adjusted that. Also changed the photocells on both burners and adjusted the drafts.
Guy that was here has 40+ years experience so I figure he know what he's doing.
Fired up and still my stack is hitting 950 degrees and not drawing syrup.
I gave the flu a brush and there was alot of soot buildup. I can only access 2/3rds without jacking everything up.
Took pans off this a.m and again there is a deposit of residue under pans.
Oil dude is back again tomorrow.
...sap is still running

[highroadsyrup]

What are you running for pump pressure? You said you changed the angle of your nozzles to 45 degree, thats not putting your fire into the back wall of the fire box by chance? What is the depth of the firebox? You can check out this site http://www.delavaninc.com/pdf/total_look.pdf it has some good info.

Good luck

[Thad Blaisdell]

Do you have enough draft?

[sugarstone]

Do you have enough draft?

We adjusted the draft.
Pump pressure is sitting at 150 psi for each burner.
I am however getting impingement on the bottom of the firebox. I have ceramic blanket over top of brick lining the arch. Even with this impingement I shouldn't still be getting 950-1000 degrees for stack temp.
One question though:
How far is the flange supposed to extend beyond the blast-tube inside the arch?

[sugarstone]

What are you running for pump pressure? You said you changed the angle of your nozzles to 45 degree, thats not putting your fire into the back wall of the fire box by chance? What is the depth of the firebox? You can check out this site http://www.delavaninc.com/pdf/total_look.pdf it has some good info.

Good luck

we are getting impingement on bottom of arch. Going to trim the blanket as I do have it overlapping for a few inches.
Don't think it will fix the heat going up the stack I'am afraid....dropping from 1000 to 600-700degrees.
I took 75% of the soot off with a brush just by reaching in from firebox. Still black though.
Dimensions of the box are 54in X 40in and 17in from bottom of pans to ceramic blanket.

[highroadsyrup]

Just made a call and your #'s all look fine for what you are running for nozzles. On the Carlin site they recommend semi solid nozzles (ss). When I told the rep your dilema he advised me of some trouble with mixtures they have experienced earlier this year w/ bio being introduced with the heating oil. Not sure if they are mixing like this where you are or not. A couple of options I can think of is maybe increasing your pump pressure above 150#. They told me it was an antomization problem, increasing the pressure should break the oil down finer. The other thing might be to add some K-1, they said there are no additives that have proven productive at this point.

Not sure anything I have suggested will help but some things to try. :confused:

[sugarstone]

Just made a call and your #'s all look fine for what you are running for nozzles. On the Carlin site they recommend semi solid nozzles (ss). When I told the rep your dilema he advised me of some trouble with mixtures they have experienced earlier this year w/ bio being introduced with the heating oil. Not sure if they are mixing like this where you are or not. A couple of options I can think of is maybe increasing your pump pressure above 150#. They told me it was an antomization problem, increasing the pressure should break the oil down finer. The other thing might be to add some K-1, they said there are no additives that have proven productive at this point.

Not sure anything I have suggested will help but some things to try. :confused:

Not sure what to do now...
Spoke to Carlin to confirm the spacing of the flange inside the "combustion chamber", aka: arch. It is .5in. Draft set at 70%
Lowered the firebox by taking out the grates and replaced with two 8in cement blocks. Layed the ceramic blanket back in.
Had a crew here today to take the flu pan out, flipped it and spent an hour getting the "insulation" off the flues. Easy Off Oven Cleaner worked well vs. Castrol Super Clean. Then the powerwasher. Not a nice day for that..high wind/wet snow here on the hill. More then a few of us had black faces.
Put flue back on, everything back together, filled up with sap, fired up and no boiling in syrup pan after an hour. Temp never reached boiling point (-5 I guess you could call it on the therm).
Drained/took pans off/flipped over and there was yellowish/reddish residue on the underside??? wtf?? This has been there before.
No evidence of impingement on ceramic blanket.
I flipped the switch to fire up the burners and they are 2.5 to maybe 3ft long and should be 4ft (should be tickling the flue).
Should I crank up the pump pressure as well as the drafts?
Any idea what the ****e is that is getting deposited on bottom of pans?

[WMF]

The yellow stuff on the bottom of the pan is common especially when starting up and the pan sweats and mixes with the combustion gases.

I would go buy enough kerosene to run a couple of hours and feed this to your burners from a separate tank. Kerosene is very pure and will burn clean if your burner is working. You obviously have a major problem with fuel or air if your front pan won't boil and you soot the whole arch.

The Carlin 601 is a fine burner, the flame should be as bright as looking at the sun and the flame ball should only be about as big as a basketball when burning 12 gph properly. If the flame is orange and lazy and luminous it will soot.

Take a very close look at the fan blades, they build up dirt and the airfoil shape changes and they make noise but don't move enough air. Make sure the burner is rotating the right direction and if the burner is enclosed make sure it can get air unrestricted.

[len]

I've seen reference to oil temp being low as a cause of incomplete combustion. I've seen mention that there are 2 types of fuel line configs, where there is a single line and one with a return back to the tank. The latter helps to preheat the oil.

What about having the gun point to a surface that will glow, to assist combustion, and deflect the heat up to the pan (set on an angle). Could be firebrick, steel plate, etc... Just an idea.